Move WebExtensions enabled Add-ons Manager

1 files changed, 2255 insertions, 0 deletions

diff --git a/toolkit/mozapps/webextensions/internal/XPIProviderUtils.js b/toolkit/mozapps/webextensions/internal/XPIProviderUtils.js
new file mode 100644
index 0000000000..d04eb207c6
--- /dev/null
+++ b/toolkit/mozapps/webextensions/internal/XPIProviderUtils.js
@@ -0,0 +1,2255 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// These are injected from XPIProvider.jsm
+/* globals ADDON_SIGNING, SIGNED_TYPES, BOOTSTRAP_REASONS, DB_SCHEMA,
+          AddonInternal, XPIProvider, XPIStates, syncLoadManifestFromFile,
+          isUsableAddon, recordAddonTelemetry, applyBlocklistChanges,
+          flushChromeCaches, canRunInSafeMode*/
+
+var Cc = Components.classes;
+var Ci = Components.interfaces;
+var Cr = Components.results;
+var Cu = Components.utils;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/AddonManager.jsm");
+/* globals AddonManagerPrivate*/
+Cu.import("resource://gre/modules/Preferences.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "AddonRepository",
+                                  "resource://gre/modules/addons/AddonRepository.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",
+                                  "resource://gre/modules/FileUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "DeferredSave",
+                                  "resource://gre/modules/DeferredSave.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Promise",
+                                  "resource://gre/modules/Promise.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "OS",
+                                  "resource://gre/modules/osfile.jsm");
+XPCOMUtils.defineLazyServiceGetter(this, "Blocklist",
+                                   "@mozilla.org/extensions/blocklist;1",
+                                   Ci.nsIBlocklistService);
+
+Cu.import("resource://gre/modules/Log.jsm");
+const LOGGER_ID = "addons.xpi-utils";
+
+const nsIFile = Components.Constructor("@mozilla.org/file/local;1", "nsIFile");
+
+// Create a new logger for use by the Addons XPI Provider Utils
+// (Requires AddonManager.jsm)
+var logger = Log.repository.getLogger(LOGGER_ID);
+
+const KEY_PROFILEDIR                  = "ProfD";
+const FILE_DATABASE                   = "extensions.sqlite";
+const FILE_JSON_DB                    = "extensions.json";
+const FILE_OLD_DATABASE               = "extensions.rdf";
+const FILE_XPI_ADDONS_LIST            = "extensions.ini";
+
+// The last version of DB_SCHEMA implemented in SQLITE
+const LAST_SQLITE_DB_SCHEMA           = 14;
+const PREF_DB_SCHEMA                  = "extensions.databaseSchema";
+const PREF_PENDING_OPERATIONS         = "extensions.pendingOperations";
+const PREF_EM_ENABLED_ADDONS          = "extensions.enabledAddons";
+const PREF_EM_DSS_ENABLED             = "extensions.dss.enabled";
+const PREF_EM_AUTO_DISABLED_SCOPES    = "extensions.autoDisableScopes";
+const PREF_E10S_BLOCKED_BY_ADDONS     = "extensions.e10sBlockedByAddons";
+const PREF_E10S_HAS_NONEXEMPT_ADDON   = "extensions.e10s.rollout.hasAddon";
+
+const KEY_APP_PROFILE                 = "app-profile";
+const KEY_APP_SYSTEM_ADDONS           = "app-system-addons";
+const KEY_APP_SYSTEM_DEFAULTS         = "app-system-defaults";
+const KEY_APP_GLOBAL                  = "app-global";
+
+// Properties that only exist in the database
+const DB_METADATA        = ["syncGUID",
+                            "installDate",
+                            "updateDate",
+                            "size",
+                            "sourceURI",
+                            "releaseNotesURI",
+                            "applyBackgroundUpdates"];
+const DB_BOOL_METADATA   = ["visible", "active", "userDisabled", "appDisabled",
+                            "pendingUninstall", "bootstrap", "skinnable",
+                            "softDisabled", "isForeignInstall",
+                            "hasBinaryComponents", "strictCompatibility"];
+
+// Properties to save in JSON file
+const PROP_JSON_FIELDS = ["id", "syncGUID", "location", "version", "type",
+                          "internalName", "updateURL", "updateKey", "optionsURL",
+                          "optionsType", "aboutURL", "icons", "iconURL", "icon64URL",
+                          "defaultLocale", "visible", "active", "userDisabled",
+                          "appDisabled", "pendingUninstall", "descriptor", "installDate",
+                          "updateDate", "applyBackgroundUpdates", "bootstrap",
+                          "skinnable", "size", "sourceURI", "releaseNotesURI",
+                          "softDisabled", "foreignInstall", "hasBinaryComponents",
+                          "strictCompatibility", "locales", "targetApplications",
+                          "targetPlatforms", "multiprocessCompatible", "signedState",
+                          "seen", "dependencies", "hasEmbeddedWebExtension", "mpcOptedOut"];
+
+// Properties that should be migrated where possible from an old database. These
+// shouldn't include properties that can be read directly from install.rdf files
+// or calculated
+const DB_MIGRATE_METADATA= ["installDate", "userDisabled", "softDisabled",
+                            "sourceURI", "applyBackgroundUpdates",
+                            "releaseNotesURI", "foreignInstall", "syncGUID"];
+
+// Time to wait before async save of XPI JSON database, in milliseconds
+const ASYNC_SAVE_DELAY_MS = 20;
+
+const PREFIX_ITEM_URI                 = "urn:mozilla:item:";
+const RDFURI_ITEM_ROOT                = "urn:mozilla:item:root"
+const PREFIX_NS_EM                    = "http://www.mozilla.org/2004/em-rdf#";
+
+XPCOMUtils.defineLazyServiceGetter(this, "gRDF", "@mozilla.org/rdf/rdf-service;1",
+                                   Ci.nsIRDFService);
+
+function EM_R(aProperty) {
+  return gRDF.GetResource(PREFIX_NS_EM + aProperty);
+}
+
+/**
+ * Converts an RDF literal, resource or integer into a string.
+ *
+ * @param  aLiteral
+ *         The RDF object to convert
+ * @return a string if the object could be converted or null
+ */
+function getRDFValue(aLiteral) {
+  if (aLiteral instanceof Ci.nsIRDFLiteral)
+    return aLiteral.Value;
+  if (aLiteral instanceof Ci.nsIRDFResource)
+    return aLiteral.Value;
+  if (aLiteral instanceof Ci.nsIRDFInt)
+    return aLiteral.Value;
+  return null;
+}
+
+/**
+ * Gets an RDF property as a string
+ *
+ * @param  aDs
+ *         The RDF datasource to read the property from
+ * @param  aResource
+ *         The RDF resource to read the property from
+ * @param  aProperty
+ *         The property to read
+ * @return a string if the property existed or null
+ */
+function getRDFProperty(aDs, aResource, aProperty) {
+  return getRDFValue(aDs.GetTarget(aResource, EM_R(aProperty), true));
+}
+
+/**
+ * Asynchronously fill in the _repositoryAddon field for one addon
+ */
+function getRepositoryAddon(aAddon, aCallback) {
+  if (!aAddon) {
+    aCallback(aAddon);
+    return;
+  }
+  function completeAddon(aRepositoryAddon) {
+    aAddon._repositoryAddon = aRepositoryAddon;
+    aAddon.compatibilityOverrides = aRepositoryAddon ?
+                                      aRepositoryAddon.compatibilityOverrides :
+                                      null;
+    aCallback(aAddon);
+  }
+  AddonRepository.getCachedAddonByID(aAddon.id, completeAddon);
+}
+
+/**
+ * Wrap an API-supplied function in an exception handler to make it safe to call
+ */
+function makeSafe(aCallback) {
+  return function(...aArgs) {
+    try {
+      aCallback(...aArgs);
+    }
+    catch (ex) {
+      logger.warn("XPI Database callback failed", ex);
+    }
+  }
+}
+
+/**
+ * A helper method to asynchronously call a function on an array
+ * of objects, calling a callback when function(x) has been gathered
+ * for every element of the array.
+ * WARNING: not currently error-safe; if the async function does not call
+ * our internal callback for any of the array elements, asyncMap will not
+ * call the callback parameter.
+ *
+ * @param  aObjects
+ *         The array of objects to process asynchronously
+ * @param  aMethod
+ *         Function with signature function(object, function(f_of_object))
+ * @param  aCallback
+ *         Function with signature f([aMethod(object)]), called when all values
+ *         are available
+ */
+function asyncMap(aObjects, aMethod, aCallback) {
+  var resultsPending = aObjects.length;
+  var results = []
+  if (resultsPending == 0) {
+    aCallback(results);
+    return;
+  }
+
+  function asyncMap_gotValue(aIndex, aValue) {
+    results[aIndex] = aValue;
+    if (--resultsPending == 0) {
+      aCallback(results);
+    }
+  }
+
+  aObjects.map(function(aObject, aIndex, aArray) {
+    try {
+      aMethod(aObject, function(aResult) {
+        asyncMap_gotValue(aIndex, aResult);
+      });
+    }
+    catch (e) {
+      logger.warn("Async map function failed", e);
+      asyncMap_gotValue(aIndex, undefined);
+    }
+  });
+}
+
+/**
+ * A generator to synchronously return result rows from an mozIStorageStatement.
+ *
+ * @param  aStatement
+ *         The statement to execute
+ */
+function* resultRows(aStatement) {
+  try {
+    while (stepStatement(aStatement))
+      yield aStatement.row;
+  }
+  finally {
+    aStatement.reset();
+  }
+}
+
+/**
+ * A helper function to log an SQL error.
+ *
+ * @param  aError
+ *         The storage error code associated with the error
+ * @param  aErrorString
+ *         An error message
+ */
+function logSQLError(aError, aErrorString) {
+  logger.error("SQL error " + aError + ": " + aErrorString);
+}
+
+/**
+ * A helper function to log any errors that occur during async statements.
+ *
+ * @param  aError
+ *         A mozIStorageError to log
+ */
+function asyncErrorLogger(aError) {
+  logSQLError(aError.result, aError.message);
+}
+
+/**
+ * A helper function to step a statement synchronously and log any error that
+ * occurs.
+ *
+ * @param  aStatement
+ *         A mozIStorageStatement to execute
+ */
+function stepStatement(aStatement) {
+  try {
+    return aStatement.executeStep();
+  }
+  catch (e) {
+    logSQLError(XPIDatabase.connection.lastError,
+                XPIDatabase.connection.lastErrorString);
+    throw e;
+  }
+}
+
+/**
+ * Copies properties from one object to another. If no target object is passed
+ * a new object will be created and returned.
+ *
+ * @param  aObject
+ *         An object to copy from
+ * @param  aProperties
+ *         An array of properties to be copied
+ * @param  aTarget
+ *         An optional target object to copy the properties to
+ * @return the object that the properties were copied onto
+ */
+function copyProperties(aObject, aProperties, aTarget) {
+  if (!aTarget)
+    aTarget = {};
+  aProperties.forEach(function(aProp) {
+    if (aProp in aObject)
+      aTarget[aProp] = aObject[aProp];
+  });
+  return aTarget;
+}
+
+/**
+ * Copies properties from a mozIStorageRow to an object. If no target object is
+ * passed a new object will be created and returned.
+ *
+ * @param  aRow
+ *         A mozIStorageRow to copy from
+ * @param  aProperties
+ *         An array of properties to be copied
+ * @param  aTarget
+ *         An optional target object to copy the properties to
+ * @return the object that the properties were copied onto
+ */
+function copyRowProperties(aRow, aProperties, aTarget) {
+  if (!aTarget)
+    aTarget = {};
+  aProperties.forEach(function(aProp) {
+    aTarget[aProp] = aRow.getResultByName(aProp);
+  });
+  return aTarget;
+}
+
+/**
+ * The DBAddonInternal is a special AddonInternal that has been retrieved from
+ * the database. The constructor will initialize the DBAddonInternal with a set
+ * of fields, which could come from either the JSON store or as an
+ * XPIProvider.AddonInternal created from an addon's manifest
+ * @constructor
+ * @param aLoaded
+ *        Addon data fields loaded from JSON or the addon manifest.
+ */
+function DBAddonInternal(aLoaded) {
+  AddonInternal.call(this);
+
+  copyProperties(aLoaded, PROP_JSON_FIELDS, this);
+
+  if (!this.dependencies)
+    this.dependencies = [];
+  Object.freeze(this.dependencies);
+
+  if (aLoaded._installLocation) {
+    this._installLocation = aLoaded._installLocation;
+    this.location = aLoaded._installLocation.name;
+  }
+  else if (aLoaded.location) {
+    this._installLocation = XPIProvider.installLocationsByName[this.location];
+  }
+
+  this._key = this.location + ":" + this.id;
+
+  if (!aLoaded._sourceBundle) {
+    throw new Error("Expected passed argument to contain a descriptor");
+  }
+
+  this._sourceBundle = aLoaded._sourceBundle;
+
+  XPCOMUtils.defineLazyGetter(this, "pendingUpgrade", function() {
+      for (let install of XPIProvider.installs) {
+        if (install.state == AddonManager.STATE_INSTALLED &&
+            !(install.addon.inDatabase) &&
+            install.addon.id == this.id &&
+            install.installLocation == this._installLocation) {
+          delete this.pendingUpgrade;
+          return this.pendingUpgrade = install.addon;
+        }
+      }
+      return null;
+    });
+}
+
+DBAddonInternal.prototype = Object.create(AddonInternal.prototype);
+Object.assign(DBAddonInternal.prototype, {
+  applyCompatibilityUpdate: function(aUpdate, aSyncCompatibility) {
+    let wasCompatible = this.isCompatible;
+
+    this.targetApplications.forEach(function(aTargetApp) {
+      aUpdate.targetApplications.forEach(function(aUpdateTarget) {
+        if (aTargetApp.id == aUpdateTarget.id && (aSyncCompatibility ||
+            Services.vc.compare(aTargetApp.maxVersion, aUpdateTarget.maxVersion) < 0)) {
+          aTargetApp.minVersion = aUpdateTarget.minVersion;
+          aTargetApp.maxVersion = aUpdateTarget.maxVersion;
+          XPIDatabase.saveChanges();
+        }
+      });
+    });
+    if (aUpdate.multiprocessCompatible !== undefined &&
+        aUpdate.multiprocessCompatible != this.multiprocessCompatible) {
+      this.multiprocessCompatible = aUpdate.multiprocessCompatible;
+      XPIDatabase.saveChanges();
+    }
+
+    if (wasCompatible != this.isCompatible)
+      XPIProvider.updateAddonDisabledState(this);
+  },
+
+  toJSON: function() {
+    let jsonData = copyProperties(this, PROP_JSON_FIELDS);
+
+    // Experiments are serialized as disabled so they aren't run on the next
+    // startup.
+    if (this.type == "experiment") {
+      jsonData.userDisabled = true;
+      jsonData.active = false;
+    }
+
+    return jsonData;
+  },
+
+  get inDatabase() {
+    return true;
+  }
+});
+
+/**
+ * Internal interface: find an addon from an already loaded addonDB
+ */
+function _findAddon(addonDB, aFilter) {
+  for (let addon of addonDB.values()) {
+    if (aFilter(addon)) {
+      return addon;
+    }
+  }
+  return null;
+}
+
+/**
+ * Internal interface to get a filtered list of addons from a loaded addonDB
+ */
+function _filterDB(addonDB, aFilter) {
+  return Array.from(addonDB.values()).filter(aFilter);
+}
+
+this.XPIDatabase = {
+  // true if the database connection has been opened
+  initialized: false,
+  // The database file
+  jsonFile: FileUtils.getFile(KEY_PROFILEDIR, [FILE_JSON_DB], true),
+  // Migration data loaded from an old version of the database.
+  migrateData: null,
+  // Active add-on directories loaded from extensions.ini and prefs at startup.
+  activeBundles: null,
+
+  // Saved error object if we fail to read an existing database
+  _loadError: null,
+
+  // Error reported by our most recent attempt to read or write the database, if any
+  get lastError() {
+    if (this._loadError)
+      return this._loadError;
+    if (this._deferredSave)
+      return this._deferredSave.lastError;
+    return null;
+  },
+
+  /**
+   * Mark the current stored data dirty, and schedule a flush to disk
+   */
+  saveChanges: function() {
+    if (!this.initialized) {
+      throw new Error("Attempt to use XPI database when it is not initialized");
+    }
+
+    if (XPIProvider._closing) {
+      // use an Error here so we get a stack trace.
+      let err = new Error("XPI database modified after shutdown began");
+      logger.warn(err);
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_late_stack", Log.stackTrace(err));
+    }
+
+    if (!this._deferredSave) {
+      this._deferredSave = new DeferredSave(this.jsonFile.path,
+                                            () => JSON.stringify(this),
+                                            ASYNC_SAVE_DELAY_MS);
+    }
+
+    this.updateAddonsBlockingE10s();
+    let promise = this._deferredSave.saveChanges();
+    if (!this._schemaVersionSet) {
+      this._schemaVersionSet = true;
+      promise = promise.then(
+        count => {
+          // Update the XPIDB schema version preference the first time we successfully
+          // save the database.
+          logger.debug("XPI Database saved, setting schema version preference to " + DB_SCHEMA);
+          Services.prefs.setIntPref(PREF_DB_SCHEMA, DB_SCHEMA);
+          // Reading the DB worked once, so we don't need the load error
+          this._loadError = null;
+        },
+        error => {
+          // Need to try setting the schema version again later
+          this._schemaVersionSet = false;
+          // this._deferredSave.lastError has the most recent error so we don't
+          // need this any more
+          this._loadError = null;
+
+          throw error;
+        });
+    }
+
+    promise.catch(error => {
+      logger.warn("Failed to save XPI database", error);
+    });
+  },
+
+  flush: function() {
+    // handle the "in memory only" and "saveChanges never called" cases
+    if (!this._deferredSave) {
+      return Promise.resolve(0);
+    }
+
+    return this._deferredSave.flush();
+  },
+
+  /**
+   * Converts the current internal state of the XPI addon database to
+   * a JSON.stringify()-ready structure
+   */
+  toJSON: function() {
+    if (!this.addonDB) {
+      // We never loaded the database?
+      throw new Error("Attempt to save database without loading it first");
+    }
+
+    let toSave = {
+      schemaVersion: DB_SCHEMA,
+      addons: [...this.addonDB.values()]
+    };
+    return toSave;
+  },
+
+  /**
+   * Pull upgrade information from an existing SQLITE database
+   *
+   * @return false if there is no SQLITE database
+   *         true and sets this.migrateData to null if the SQLITE DB exists
+   *              but does not contain useful information
+   *         true and sets this.migrateData to
+   *              {location: {id1:{addon1}, id2:{addon2}}, location2:{...}, ...}
+   *              if there is useful information
+   */
+  getMigrateDataFromSQLITE: function() {
+    let connection = null;
+    let dbfile = FileUtils.getFile(KEY_PROFILEDIR, [FILE_DATABASE], true);
+    // Attempt to open the database
+    try {
+      connection = Services.storage.openUnsharedDatabase(dbfile);
+    }
+    catch (e) {
+      logger.warn("Failed to open sqlite database " + dbfile.path + " for upgrade", e);
+      return null;
+    }
+    logger.debug("Migrating data from sqlite");
+    let migrateData = this.getMigrateDataFromDatabase(connection);
+    connection.close();
+    return migrateData;
+  },
+
+  /**
+   * Synchronously opens and reads the database file, upgrading from old
+   * databases or making a new DB if needed.
+   *
+   * The possibilities, in order of priority, are:
+   * 1) Perfectly good, up to date database
+   * 2) Out of date JSON database needs to be upgraded => upgrade
+   * 3) JSON database exists but is mangled somehow => build new JSON
+   * 4) no JSON DB, but a useable SQLITE db we can upgrade from => upgrade
+   * 5) useless SQLITE DB => build new JSON
+   * 6) useable RDF DB => upgrade
+   * 7) useless RDF DB => build new JSON
+   * 8) Nothing at all => build new JSON
+   * @param  aRebuildOnError
+   *         A boolean indicating whether add-on information should be loaded
+   *         from the install locations if the database needs to be rebuilt.
+   *         (if false, caller is XPIProvider.checkForChanges() which will rebuild)
+   */
+  syncLoadDB: function(aRebuildOnError) {
+    this.migrateData = null;
+    let fstream = null;
+    let data = "";
+    try {
+      let readTimer = AddonManagerPrivate.simpleTimer("XPIDB_syncRead_MS");
+      logger.debug("Opening XPI database " + this.jsonFile.path);
+      fstream = Components.classes["@mozilla.org/network/file-input-stream;1"].
+              createInstance(Components.interfaces.nsIFileInputStream);
+      fstream.init(this.jsonFile, -1, 0, 0);
+      let cstream = null;
+      try {
+        cstream = Components.classes["@mozilla.org/intl/converter-input-stream;1"].
+                createInstance(Components.interfaces.nsIConverterInputStream);
+        cstream.init(fstream, "UTF-8", 0, 0);
+
+        let str = {};
+        let read = 0;
+        do {
+          read = cstream.readString(0xffffffff, str); // read as much as we can and put it in str.value
+          data += str.value;
+        } while (read != 0);
+
+        readTimer.done();
+        this.parseDB(data, aRebuildOnError);
+      }
+      catch (e) {
+        logger.error("Failed to load XPI JSON data from profile", e);
+        let rebuildTimer = AddonManagerPrivate.simpleTimer("XPIDB_rebuildReadFailed_MS");
+        this.rebuildDatabase(aRebuildOnError);
+        rebuildTimer.done();
+      }
+      finally {
+        if (cstream)
+          cstream.close();
+      }
+    }
+    catch (e) {
+      if (e.result === Cr.NS_ERROR_FILE_NOT_FOUND) {
+        this.upgradeDB(aRebuildOnError);
+      }
+      else {
+        this.rebuildUnreadableDB(e, aRebuildOnError);
+      }
+    }
+    finally {
+      if (fstream)
+        fstream.close();
+    }
+    // If an async load was also in progress, resolve that promise with our DB;
+    // otherwise create a resolved promise
+    if (this._dbPromise) {
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_overlapped_load", 1);
+      this._dbPromise.resolve(this.addonDB);
+    }
+    else
+      this._dbPromise = Promise.resolve(this.addonDB);
+  },
+
+  /**
+   * Parse loaded data, reconstructing the database if the loaded data is not valid
+   * @param aRebuildOnError
+   *        If true, synchronously reconstruct the database from installed add-ons
+   */
+  parseDB: function(aData, aRebuildOnError) {
+    let parseTimer = AddonManagerPrivate.simpleTimer("XPIDB_parseDB_MS");
+    try {
+      // dump("Loaded JSON:\n" + aData + "\n");
+      let inputAddons = JSON.parse(aData);
+      // Now do some sanity checks on our JSON db
+      if (!("schemaVersion" in inputAddons) || !("addons" in inputAddons)) {
+        parseTimer.done();
+        // Content of JSON file is bad, need to rebuild from scratch
+        logger.error("bad JSON file contents");
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError", "badJSON");
+        let rebuildTimer = AddonManagerPrivate.simpleTimer("XPIDB_rebuildBadJSON_MS");
+        this.rebuildDatabase(aRebuildOnError);
+        rebuildTimer.done();
+        return;
+      }
+      if (inputAddons.schemaVersion != DB_SCHEMA) {
+        // Handle mismatched JSON schema version. For now, we assume
+        // compatibility for JSON data, though we throw away any fields we
+        // don't know about (bug 902956)
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError",
+                                                "schemaMismatch-" + inputAddons.schemaVersion);
+        logger.debug("JSON schema mismatch: expected " + DB_SCHEMA +
+            ", actual " + inputAddons.schemaVersion);
+        // When we rev the schema of the JSON database, we need to make sure we
+        // force the DB to save so that the DB_SCHEMA value in the JSON file and
+        // the preference are updated.
+      }
+      // If we got here, we probably have good data
+      // Make AddonInternal instances from the loaded data and save them
+      let addonDB = new Map();
+      for (let loadedAddon of inputAddons.addons) {
+        loadedAddon._sourceBundle = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
+        try {
+          loadedAddon._sourceBundle.persistentDescriptor = loadedAddon.descriptor;
+        }
+        catch (e) {
+          // We can fail here when the descriptor is invalid, usually from the
+          // wrong OS
+          logger.warn("Could not find source bundle for add-on " + loadedAddon.id, e);
+        }
+
+        let newAddon = new DBAddonInternal(loadedAddon);
+        addonDB.set(newAddon._key, newAddon);
+      }
+      parseTimer.done();
+      this.addonDB = addonDB;
+      logger.debug("Successfully read XPI database");
+      this.initialized = true;
+    }
+    catch (e) {
+      // If we catch and log a SyntaxError from the JSON
+      // parser, the xpcshell test harness fails the test for us: bug 870828
+      parseTimer.done();
+      if (e.name == "SyntaxError") {
+        logger.error("Syntax error parsing saved XPI JSON data");
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError", "syntax");
+      }
+      else {
+        logger.error("Failed to load XPI JSON data from profile", e);
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError", "other");
+      }
+      let rebuildTimer = AddonManagerPrivate.simpleTimer("XPIDB_rebuildReadFailed_MS");
+      this.rebuildDatabase(aRebuildOnError);
+      rebuildTimer.done();
+    }
+  },
+
+  /**
+   * Upgrade database from earlier (sqlite or RDF) version if available
+   */
+  upgradeDB: function(aRebuildOnError) {
+    let upgradeTimer = AddonManagerPrivate.simpleTimer("XPIDB_upgradeDB_MS");
+    try {
+      let schemaVersion = Services.prefs.getIntPref(PREF_DB_SCHEMA);
+      if (schemaVersion <= LAST_SQLITE_DB_SCHEMA) {
+        // we should have an older SQLITE database
+        logger.debug("Attempting to upgrade from SQLITE database");
+        this.migrateData = this.getMigrateDataFromSQLITE();
+      }
+      else {
+        // we've upgraded before but the JSON file is gone, fall through
+        // and rebuild from scratch
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError", "dbMissing");
+      }
+    }
+    catch (e) {
+      // No schema version pref means either a really old upgrade (RDF) or
+      // a new profile
+      this.migrateData = this.getMigrateDataFromRDF();
+    }
+
+    this.rebuildDatabase(aRebuildOnError);
+    upgradeTimer.done();
+  },
+
+  /**
+   * Reconstruct when the DB file exists but is unreadable
+   * (for example because read permission is denied)
+   */
+  rebuildUnreadableDB: function(aError, aRebuildOnError) {
+    let rebuildTimer = AddonManagerPrivate.simpleTimer("XPIDB_rebuildUnreadableDB_MS");
+    logger.warn("Extensions database " + this.jsonFile.path +
+        " exists but is not readable; rebuilding", aError);
+    // Remember the error message until we try and write at least once, so
+    // we know at shutdown time that there was a problem
+    this._loadError = aError;
+    AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError", "unreadable");
+    this.rebuildDatabase(aRebuildOnError);
+    rebuildTimer.done();
+  },
+
+  /**
+   * Open and read the XPI database asynchronously, upgrading if
+   * necessary. If any DB load operation fails, we need to
+   * synchronously rebuild the DB from the installed extensions.
+   *
+   * @return Promise<Map> resolves to the Map of loaded JSON data stored
+   *         in this.addonDB; never rejects.
+   */
+  asyncLoadDB: function() {
+    // Already started (and possibly finished) loading
+    if (this._dbPromise) {
+      return this._dbPromise;
+    }
+
+    logger.debug("Starting async load of XPI database " + this.jsonFile.path);
+    AddonManagerPrivate.recordSimpleMeasure("XPIDB_async_load", XPIProvider.runPhase);
+    let readOptions = {
+      outExecutionDuration: 0
+    };
+    return this._dbPromise = OS.File.read(this.jsonFile.path, null, readOptions).then(
+      byteArray => {
+        logger.debug("Async JSON file read took " + readOptions.outExecutionDuration + " MS");
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_asyncRead_MS",
+          readOptions.outExecutionDuration);
+        if (this._addonDB) {
+          logger.debug("Synchronous load completed while waiting for async load");
+          return this.addonDB;
+        }
+        logger.debug("Finished async read of XPI database, parsing...");
+        let decodeTimer = AddonManagerPrivate.simpleTimer("XPIDB_decode_MS");
+        let decoder = new TextDecoder();
+        let data = decoder.decode(byteArray);
+        decodeTimer.done();
+        this.parseDB(data, true);
+        return this.addonDB;
+      })
+    .then(null,
+      error => {
+        if (this._addonDB) {
+          logger.debug("Synchronous load completed while waiting for async load");
+          return this.addonDB;
+        }
+        if (error.becauseNoSuchFile) {
+          this.upgradeDB(true);
+        }
+        else {
+          // it's there but unreadable
+          this.rebuildUnreadableDB(error, true);
+        }
+        return this.addonDB;
+      });
+  },
+
+  /**
+   * Rebuild the database from addon install directories. If this.migrateData
+   * is available, uses migrated information for settings on the addons found
+   * during rebuild
+   * @param aRebuildOnError
+   *         A boolean indicating whether add-on information should be loaded
+   *         from the install locations if the database needs to be rebuilt.
+   *         (if false, caller is XPIProvider.checkForChanges() which will rebuild)
+   */
+  rebuildDatabase: function(aRebuildOnError) {
+    this.addonDB = new Map();
+    this.initialized = true;
+
+    if (XPIStates.size == 0) {
+      // No extensions installed, so we're done
+      logger.debug("Rebuilding XPI database with no extensions");
+      return;
+    }
+
+    // If there is no migration data then load the list of add-on directories
+    // that were active during the last run
+    if (!this.migrateData)
+      this.activeBundles = this.getActiveBundles();
+
+    if (aRebuildOnError) {
+      logger.warn("Rebuilding add-ons database from installed extensions.");
+      try {
+        XPIDatabaseReconcile.processFileChanges({}, false);
+      }
+      catch (e) {
+        logger.error("Failed to rebuild XPI database from installed extensions", e);
+      }
+      // Make sure to update the active add-ons and add-ons list on shutdown
+      Services.prefs.setBoolPref(PREF_PENDING_OPERATIONS, true);
+    }
+  },
+
+  /**
+   * Gets the list of file descriptors of active extension directories or XPI
+   * files from the add-ons list. This must be loaded from disk since the
+   * directory service gives no easy way to get both directly. This list doesn't
+   * include themes as preferences already say which theme is currently active
+   *
+   * @return an array of persistent descriptors for the directories
+   */
+  getActiveBundles: function() {
+    let bundles = [];
+
+    // non-bootstrapped extensions
+    let addonsList = FileUtils.getFile(KEY_PROFILEDIR, [FILE_XPI_ADDONS_LIST],
+                                       true);
+
+    if (!addonsList.exists())
+      // XXX Irving believes this is broken in the case where there is no
+      // extensions.ini but there are bootstrap extensions (e.g. Android)
+      return null;
+
+    try {
+      let iniFactory = Cc["@mozilla.org/xpcom/ini-parser-factory;1"]
+                         .getService(Ci.nsIINIParserFactory);
+      let parser = iniFactory.createINIParser(addonsList);
+      let keys = parser.getKeys("ExtensionDirs");
+
+      while (keys.hasMore())
+        bundles.push(parser.getString("ExtensionDirs", keys.getNext()));
+    }
+    catch (e) {
+      logger.warn("Failed to parse extensions.ini", e);
+      return null;
+    }
+
+    // Also include the list of active bootstrapped extensions
+    for (let id in XPIProvider.bootstrappedAddons)
+      bundles.push(XPIProvider.bootstrappedAddons[id].descriptor);
+
+    return bundles;
+  },
+
+  /**
+   * Retrieves migration data from the old extensions.rdf database.
+   *
+   * @return an object holding information about what add-ons were previously
+   *         userDisabled and any updated compatibility information
+   */
+  getMigrateDataFromRDF: function(aDbWasMissing) {
+
+    // Migrate data from extensions.rdf
+    let rdffile = FileUtils.getFile(KEY_PROFILEDIR, [FILE_OLD_DATABASE], true);
+    if (!rdffile.exists())
+      return null;
+
+    logger.debug("Migrating data from " + FILE_OLD_DATABASE);
+    let migrateData = {};
+
+    try {
+      let ds = gRDF.GetDataSourceBlocking(Services.io.newFileURI(rdffile).spec);
+      let root = Cc["@mozilla.org/rdf/container;1"].
+                 createInstance(Ci.nsIRDFContainer);
+      root.Init(ds, gRDF.GetResource(RDFURI_ITEM_ROOT));
+      let elements = root.GetElements();
+
+      while (elements.hasMoreElements()) {
+        let source = elements.getNext().QueryInterface(Ci.nsIRDFResource);
+
+        let location = getRDFProperty(ds, source, "installLocation");
+        if (location) {
+          if (!(location in migrateData))
+            migrateData[location] = {};
+          let id = source.ValueUTF8.substring(PREFIX_ITEM_URI.length);
+          migrateData[location][id] = {
+            version: getRDFProperty(ds, source, "version"),
+            userDisabled: false,
+            targetApplications: []
+          }
+
+          let disabled = getRDFProperty(ds, source, "userDisabled");
+          if (disabled == "true" || disabled == "needs-disable")
+            migrateData[location][id].userDisabled = true;
+
+          let targetApps = ds.GetTargets(source, EM_R("targetApplication"),
+                                         true);
+          while (targetApps.hasMoreElements()) {
+            let targetApp = targetApps.getNext()
+                                      .QueryInterface(Ci.nsIRDFResource);
+            let appInfo = {
+              id: getRDFProperty(ds, targetApp, "id")
+            };
+
+            let minVersion = getRDFProperty(ds, targetApp, "updatedMinVersion");
+            if (minVersion) {
+              appInfo.minVersion = minVersion;
+              appInfo.maxVersion = getRDFProperty(ds, targetApp, "updatedMaxVersion");
+            }
+            else {
+              appInfo.minVersion = getRDFProperty(ds, targetApp, "minVersion");
+              appInfo.maxVersion = getRDFProperty(ds, targetApp, "maxVersion");
+            }
+            migrateData[location][id].targetApplications.push(appInfo);
+          }
+        }
+      }
+    }
+    catch (e) {
+      logger.warn("Error reading " + FILE_OLD_DATABASE, e);
+      migrateData = null;
+    }
+
+    return migrateData;
+  },
+
+  /**
+   * Retrieves migration data from a database that has an older or newer schema.
+   *
+   * @return an object holding information about what add-ons were previously
+   *         userDisabled and any updated compatibility information
+   */
+  getMigrateDataFromDatabase: function(aConnection) {
+    let migrateData = {};
+
+    // Attempt to migrate data from a different (even future!) version of the
+    // database
+    try {
+      var stmt = aConnection.createStatement("PRAGMA table_info(addon)");
+
+      const REQUIRED = ["internal_id", "id", "location", "userDisabled",
+                        "installDate", "version"];
+
+      let reqCount = 0;
+      let props = [];
+      for (let row of resultRows(stmt)) {
+        if (REQUIRED.indexOf(row.name) != -1) {
+          reqCount++;
+          props.push(row.name);
+        }
+        else if (DB_METADATA.indexOf(row.name) != -1) {
+          props.push(row.name);
+        }
+        else if (DB_BOOL_METADATA.indexOf(row.name) != -1) {
+          props.push(row.name);
+        }
+      }
+
+      if (reqCount < REQUIRED.length) {
+        logger.error("Unable to read anything useful from the database");
+        return null;
+      }
+      stmt.finalize();
+
+      stmt = aConnection.createStatement("SELECT " + props.join(",") + " FROM addon");
+      for (let row of resultRows(stmt)) {
+        if (!(row.location in migrateData))
+          migrateData[row.location] = {};
+        let addonData = {
+          targetApplications: []
+        }
+        migrateData[row.location][row.id] = addonData;
+
+        props.forEach(function(aProp) {
+          if (aProp == "isForeignInstall")
+            addonData.foreignInstall = (row[aProp] == 1);
+          if (DB_BOOL_METADATA.indexOf(aProp) != -1)
+            addonData[aProp] = row[aProp] == 1;
+          else
+            addonData[aProp] = row[aProp];
+        })
+      }
+
+      var taStmt = aConnection.createStatement("SELECT id, minVersion, " +
+                                                   "maxVersion FROM " +
+                                                   "targetApplication WHERE " +
+                                                   "addon_internal_id=:internal_id");
+
+      for (let location in migrateData) {
+        for (let id in migrateData[location]) {
+          taStmt.params.internal_id = migrateData[location][id].internal_id;
+          delete migrateData[location][id].internal_id;
+          for (let row of resultRows(taStmt)) {
+            migrateData[location][id].targetApplications.push({
+              id: row.id,
+              minVersion: row.minVersion,
+              maxVersion: row.maxVersion
+            });
+          }
+        }
+      }
+    }
+    catch (e) {
+      // An error here means the schema is too different to read
+      logger.error("Error migrating data", e);
+      return null;
+    }
+    finally {
+      if (taStmt)
+        taStmt.finalize();
+      if (stmt)
+        stmt.finalize();
+    }
+
+    return migrateData;
+  },
+
+  /**
+   * Shuts down the database connection and releases all cached objects.
+   * Return: Promise{integer} resolves / rejects with the result of the DB
+   *                          flush after the database is flushed and
+   *                          all cleanup is done
+   */
+  shutdown: function() {
+    logger.debug("shutdown");
+    if (this.initialized) {
+      // If our last database I/O had an error, try one last time to save.
+      if (this.lastError)
+        this.saveChanges();
+
+      this.initialized = false;
+
+      if (this._deferredSave) {
+        AddonManagerPrivate.recordSimpleMeasure(
+            "XPIDB_saves_total", this._deferredSave.totalSaves);
+        AddonManagerPrivate.recordSimpleMeasure(
+            "XPIDB_saves_overlapped", this._deferredSave.overlappedSaves);
+        AddonManagerPrivate.recordSimpleMeasure(
+            "XPIDB_saves_late", this._deferredSave.dirty ? 1 : 0);
+      }
+
+      // Return a promise that any pending writes of the DB are complete and we
+      // are finished cleaning up
+      let flushPromise = this.flush();
+      flushPromise.then(null, error => {
+          logger.error("Flush of XPI database failed", error);
+          AddonManagerPrivate.recordSimpleMeasure("XPIDB_shutdownFlush_failed", 1);
+          // If our last attempt to read or write the DB failed, force a new
+          // extensions.ini to be written to disk on the next startup
+          Services.prefs.setBoolPref(PREF_PENDING_OPERATIONS, true);
+        })
+        .then(count => {
+          // Clear out the cached addons data loaded from JSON
+          delete this.addonDB;
+          delete this._dbPromise;
+          // same for the deferred save
+          delete this._deferredSave;
+          // re-enable the schema version setter
+          delete this._schemaVersionSet;
+        });
+      return flushPromise;
+    }
+    return Promise.resolve(0);
+  },
+
+  /**
+   * Asynchronously list all addons that match the filter function
+   * @param  aFilter
+   *         Function that takes an addon instance and returns
+   *         true if that addon should be included in the selected array
+   * @param  aCallback
+   *         Called back with an array of addons matching aFilter
+   *         or an empty array if none match
+   */
+  getAddonList: function(aFilter, aCallback) {
+    this.asyncLoadDB().then(
+      addonDB => {
+        let addonList = _filterDB(addonDB, aFilter);
+        asyncMap(addonList, getRepositoryAddon, makeSafe(aCallback));
+      })
+    .then(null,
+        error => {
+          logger.error("getAddonList failed", error);
+          makeSafe(aCallback)([]);
+        });
+  },
+
+  /**
+   * (Possibly asynchronously) get the first addon that matches the filter function
+   * @param  aFilter
+   *         Function that takes an addon instance and returns
+   *         true if that addon should be selected
+   * @param  aCallback
+   *         Called back with the addon, or null if no matching addon is found
+   */
+  getAddon: function(aFilter, aCallback) {
+    return this.asyncLoadDB().then(
+      addonDB => {
+        getRepositoryAddon(_findAddon(addonDB, aFilter), makeSafe(aCallback));
+      })
+    .then(null,
+        error => {
+          logger.error("getAddon failed", error);
+          makeSafe(aCallback)(null);
+        });
+  },
+
+  /**
+   * Asynchronously gets an add-on with a particular ID in a particular
+   * install location.
+   *
+   * @param  aId
+   *         The ID of the add-on to retrieve
+   * @param  aLocation
+   *         The name of the install location
+   * @param  aCallback
+   *         A callback to pass the DBAddonInternal to
+   */
+  getAddonInLocation: function(aId, aLocation, aCallback) {
+    this.asyncLoadDB().then(
+        addonDB => getRepositoryAddon(addonDB.get(aLocation + ":" + aId),
+                                      makeSafe(aCallback)));
+  },
+
+  /**
+   * Asynchronously get all the add-ons in a particular install location.
+   *
+   * @param  aLocation
+   *         The name of the install location
+   * @param  aCallback
+   *         A callback to pass the array of DBAddonInternals to
+   */
+  getAddonsInLocation: function(aLocation, aCallback) {
+    this.getAddonList(aAddon => aAddon._installLocation.name == aLocation, aCallback);
+  },
+
+  /**
+   * Asynchronously gets the add-on with the specified ID that is visible.
+   *
+   * @param  aId
+   *         The ID of the add-on to retrieve
+   * @param  aCallback
+   *         A callback to pass the DBAddonInternal to
+   */
+  getVisibleAddonForID: function(aId, aCallback) {
+    this.getAddon(aAddon => ((aAddon.id == aId) && aAddon.visible),
+                  aCallback);
+  },
+
+  /**
+   * Asynchronously gets the visible add-ons, optionally restricting by type.
+   *
+   * @param  aTypes
+   *         An array of types to include or null to include all types
+   * @param  aCallback
+   *         A callback to pass the array of DBAddonInternals to
+   */
+  getVisibleAddons: function(aTypes, aCallback) {
+    this.getAddonList(aAddon => (aAddon.visible &&
+                                 (!aTypes || (aTypes.length == 0) ||
+                                  (aTypes.indexOf(aAddon.type) > -1))),
+                      aCallback);
+  },
+
+  /**
+   * Synchronously gets all add-ons of a particular type.
+   *
+   * @param  aType
+   *         The type of add-on to retrieve
+   * @return an array of DBAddonInternals
+   */
+  getAddonsByType: function(aType) {
+    if (!this.addonDB) {
+      // jank-tastic! Must synchronously load DB if the theme switches from
+      // an XPI theme to a lightweight theme before the DB has loaded,
+      // because we're called from sync XPIProvider.addonChanged
+      logger.warn("Synchronous load of XPI database due to getAddonsByType(" + aType + ")");
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_lateOpen_byType", XPIProvider.runPhase);
+      this.syncLoadDB(true);
+    }
+    return _filterDB(this.addonDB, aAddon => (aAddon.type == aType));
+  },
+
+  /**
+   * Synchronously gets an add-on with a particular internalName.
+   *
+   * @param  aInternalName
+   *         The internalName of the add-on to retrieve
+   * @return a DBAddonInternal
+   */
+  getVisibleAddonForInternalName: function(aInternalName) {
+    if (!this.addonDB) {
+      // This may be called when the DB hasn't otherwise been loaded
+      logger.warn("Synchronous load of XPI database due to getVisibleAddonForInternalName");
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_lateOpen_forInternalName",
+          XPIProvider.runPhase);
+      this.syncLoadDB(true);
+    }
+
+    return _findAddon(this.addonDB,
+                      aAddon => aAddon.visible &&
+                                (aAddon.internalName == aInternalName));
+  },
+
+  /**
+   * Asynchronously gets all add-ons with pending operations.
+   *
+   * @param  aTypes
+   *         The types of add-ons to retrieve or null to get all types
+   * @param  aCallback
+   *         A callback to pass the array of DBAddonInternal to
+   */
+  getVisibleAddonsWithPendingOperations: function(aTypes, aCallback) {
+    this.getAddonList(
+        aAddon => (aAddon.visible &&
+                   (aAddon.pendingUninstall ||
+                    // Logic here is tricky. If we're active but disabled,
+                    // we're pending disable; !active && !disabled, we're pending enable
+                    (aAddon.active == aAddon.disabled)) &&
+                   (!aTypes || (aTypes.length == 0) || (aTypes.indexOf(aAddon.type) > -1))),
+        aCallback);
+  },
+
+  /**
+   * Asynchronously get an add-on by its Sync GUID.
+   *
+   * @param  aGUID
+   *         Sync GUID of add-on to fetch
+   * @param  aCallback
+   *         A callback to pass the DBAddonInternal record to. Receives null
+   *         if no add-on with that GUID is found.
+   *
+   */
+  getAddonBySyncGUID: function(aGUID, aCallback) {
+    this.getAddon(aAddon => aAddon.syncGUID == aGUID,
+                  aCallback);
+  },
+
+  /**
+   * Synchronously gets all add-ons in the database.
+   * This is only called from the preference observer for the default
+   * compatibility version preference, so we can return an empty list if
+   * we haven't loaded the database yet.
+   *
+   * @return  an array of DBAddonInternals
+   */
+  getAddons: function() {
+    if (!this.addonDB) {
+      return [];
+    }
+    return _filterDB(this.addonDB, aAddon => true);
+  },
+
+  /**
+   * Synchronously adds an AddonInternal's metadata to the database.
+   *
+   * @param  aAddon
+   *         AddonInternal to add
+   * @param  aDescriptor
+   *         The file descriptor of the add-on
+   * @return The DBAddonInternal that was added to the database
+   */
+  addAddonMetadata: function(aAddon, aDescriptor) {
+    if (!this.addonDB) {
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_lateOpen_addMetadata",
+          XPIProvider.runPhase);
+      this.syncLoadDB(false);
+    }
+
+    let newAddon = new DBAddonInternal(aAddon);
+    newAddon.descriptor = aDescriptor;
+    this.addonDB.set(newAddon._key, newAddon);
+    if (newAddon.visible) {
+      this.makeAddonVisible(newAddon);
+    }
+
+    this.saveChanges();
+    return newAddon;
+  },
+
+  /**
+   * Synchronously updates an add-on's metadata in the database. Currently just
+   * removes and recreates.
+   *
+   * @param  aOldAddon
+   *         The DBAddonInternal to be replaced
+   * @param  aNewAddon
+   *         The new AddonInternal to add
+   * @param  aDescriptor
+   *         The file descriptor of the add-on
+   * @return The DBAddonInternal that was added to the database
+   */
+  updateAddonMetadata: function(aOldAddon, aNewAddon, aDescriptor) {
+    this.removeAddonMetadata(aOldAddon);
+    aNewAddon.syncGUID = aOldAddon.syncGUID;
+    aNewAddon.installDate = aOldAddon.installDate;
+    aNewAddon.applyBackgroundUpdates = aOldAddon.applyBackgroundUpdates;
+    aNewAddon.foreignInstall = aOldAddon.foreignInstall;
+    aNewAddon.seen = aOldAddon.seen;
+    aNewAddon.active = (aNewAddon.visible && !aNewAddon.disabled && !aNewAddon.pendingUninstall);
+
+    // addAddonMetadata does a saveChanges()
+    return this.addAddonMetadata(aNewAddon, aDescriptor);
+  },
+
+  /**
+   * Synchronously removes an add-on from the database.
+   *
+   * @param  aAddon
+   *         The DBAddonInternal being removed
+   */
+  removeAddonMetadata: function(aAddon) {
+    this.addonDB.delete(aAddon._key);
+    this.saveChanges();
+  },
+
+  /**
+   * Synchronously marks a DBAddonInternal as visible marking all other
+   * instances with the same ID as not visible.
+   *
+   * @param  aAddon
+   *         The DBAddonInternal to make visible
+   */
+  makeAddonVisible: function(aAddon) {
+    logger.debug("Make addon " + aAddon._key + " visible");
+    for (let [, otherAddon] of this.addonDB) {
+      if ((otherAddon.id == aAddon.id) && (otherAddon._key != aAddon._key)) {
+        logger.debug("Hide addon " + otherAddon._key);
+        otherAddon.visible = false;
+        otherAddon.active = false;
+      }
+    }
+    aAddon.visible = true;
+    this.saveChanges();
+  },
+
+  /**
+   * Synchronously sets properties for an add-on.
+   *
+   * @param  aAddon
+   *         The DBAddonInternal being updated
+   * @param  aProperties
+   *         A dictionary of properties to set
+   */
+  setAddonProperties: function(aAddon, aProperties) {
+    for (let key in aProperties) {
+      aAddon[key] = aProperties[key];
+    }
+    this.saveChanges();
+  },
+
+  /**
+   * Synchronously sets the Sync GUID for an add-on.
+   * Only called when the database is already loaded.
+   *
+   * @param  aAddon
+   *         The DBAddonInternal being updated
+   * @param  aGUID
+   *         GUID string to set the value to
+   * @throws if another addon already has the specified GUID
+   */
+  setAddonSyncGUID: function(aAddon, aGUID) {
+    // Need to make sure no other addon has this GUID
+    function excludeSyncGUID(otherAddon) {
+      return (otherAddon._key != aAddon._key) && (otherAddon.syncGUID == aGUID);
+    }
+    let otherAddon = _findAddon(this.addonDB, excludeSyncGUID);
+    if (otherAddon) {
+      throw new Error("Addon sync GUID conflict for addon " + aAddon._key +
+          ": " + otherAddon._key + " already has GUID " + aGUID);
+    }
+    aAddon.syncGUID = aGUID;
+    this.saveChanges();
+  },
+
+  /**
+   * Synchronously updates an add-on's active flag in the database.
+   *
+   * @param  aAddon
+   *         The DBAddonInternal to update
+   */
+  updateAddonActive: function(aAddon, aActive) {
+    logger.debug("Updating active state for add-on " + aAddon.id + " to " + aActive);
+
+    aAddon.active = aActive;
+    this.saveChanges();
+  },
+
+  updateAddonsBlockingE10s: function() {
+    let blockE10s = false;
+
+    Preferences.set(PREF_E10S_HAS_NONEXEMPT_ADDON, false);
+    for (let [, addon] of this.addonDB) {
+      let active = (addon.visible && !addon.disabled && !addon.pendingUninstall);
+
+      if (active && XPIProvider.isBlockingE10s(addon)) {
+        blockE10s = true;
+        break;
+      }
+    }
+    Preferences.set(PREF_E10S_BLOCKED_BY_ADDONS, blockE10s);
+  },
+
+  /**
+   * Synchronously calculates and updates all the active flags in the database.
+   */
+  updateActiveAddons: function() {
+    if (!this.addonDB) {
+      logger.warn("updateActiveAddons called when DB isn't loaded");
+      // force the DB to load
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_lateOpen_updateActive",
+          XPIProvider.runPhase);
+      this.syncLoadDB(true);
+    }
+    logger.debug("Updating add-on states");
+    for (let [, addon] of this.addonDB) {
+      let newActive = (addon.visible && !addon.disabled && !addon.pendingUninstall);
+      if (newActive != addon.active) {
+        addon.active = newActive;
+        this.saveChanges();
+      }
+    }
+  },
+
+  /**
+   * Writes out the XPI add-ons list for the platform to read.
+   * @return true if the file was successfully updated, false otherwise
+   */
+  writeAddonsList: function() {
+    if (!this.addonDB) {
+      // force the DB to load
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_lateOpen_writeList",
+          XPIProvider.runPhase);
+      this.syncLoadDB(true);
+    }
+    Services.appinfo.invalidateCachesOnRestart();
+
+    let addonsList = FileUtils.getFile(KEY_PROFILEDIR, [FILE_XPI_ADDONS_LIST],
+                                       true);
+    let enabledAddons = [];
+    let text = "[ExtensionDirs]\r\n";
+    let count = 0;
+    let fullCount = 0;
+
+    let activeAddons = _filterDB(
+      this.addonDB,
+      aAddon => aAddon.active && !aAddon.bootstrap && (aAddon.type != "theme"));
+
+    for (let row of activeAddons) {
+      text += "Extension" + (count++) + "=" + row.descriptor + "\r\n";
+      enabledAddons.push(encodeURIComponent(row.id) + ":" +
+                         encodeURIComponent(row.version));
+    }
+    fullCount += count;
+
+    // The selected skin may come from an inactive theme (the default theme
+    // when a lightweight theme is applied for example)
+    text += "\r\n[ThemeDirs]\r\n";
+
+    let dssEnabled = false;
+    try {
+      dssEnabled = Services.prefs.getBoolPref(PREF_EM_DSS_ENABLED);
+    } catch (e) {}
+
+    let themes = [];
+    if (dssEnabled) {
+      themes = _filterDB(this.addonDB, aAddon => aAddon.type == "theme");
+    }
+    else {
+      let activeTheme = _findAddon(
+        this.addonDB,
+        aAddon => (aAddon.type == "theme") &&
+                  (aAddon.internalName == XPIProvider.selectedSkin));
+      if (activeTheme) {
+        themes.push(activeTheme);
+      }
+    }
+
+    if (themes.length > 0) {
+      count = 0;
+      for (let row of themes) {
+        text += "Extension" + (count++) + "=" + row.descriptor + "\r\n";
+        enabledAddons.push(encodeURIComponent(row.id) + ":" +
+                           encodeURIComponent(row.version));
+      }
+      fullCount += count;
+    }
+
+    text += "\r\n[MultiprocessIncompatibleExtensions]\r\n";
+
+    count = 0;
+    for (let row of activeAddons) {
+      if (!row.multiprocessCompatible) {
+        text += "Extension" + (count++) + "=" + row.id + "\r\n";
+      }
+    }
+
+    if (fullCount > 0) {
+      logger.debug("Writing add-ons list");
+
+      try {
+        let addonsListTmp = FileUtils.getFile(KEY_PROFILEDIR, [FILE_XPI_ADDONS_LIST + ".tmp"],
+                                              true);
+        var fos = FileUtils.openFileOutputStream(addonsListTmp);
+        fos.write(text, text.length);
+        fos.close();
+        addonsListTmp.moveTo(addonsListTmp.parent, FILE_XPI_ADDONS_LIST);
+
+        Services.prefs.setCharPref(PREF_EM_ENABLED_ADDONS, enabledAddons.join(","));
+      }
+      catch (e) {
+        logger.error("Failed to write add-ons list to profile directory", e);
+        return false;
+      }
+    }
+    else {
+      if (addonsList.exists()) {
+        logger.debug("Deleting add-ons list");
+        try {
+          addonsList.remove(false);
+        }
+        catch (e) {
+          logger.error("Failed to remove " + addonsList.path, e);
+          return false;
+        }
+      }
+
+      Services.prefs.clearUserPref(PREF_EM_ENABLED_ADDONS);
+    }
+    return true;
+  }
+};
+
+this.XPIDatabaseReconcile = {
+  /**
+   * Returns a map of ID -> add-on. When the same add-on ID exists in multiple
+   * install locations the highest priority location is chosen.
+   */
+  flattenByID(addonMap, hideLocation) {
+    let map = new Map();
+
+    for (let installLocation of XPIProvider.installLocations) {
+      if (installLocation.name == hideLocation)
+        continue;
+
+      let locationMap = addonMap.get(installLocation.name);
+      if (!locationMap)
+        continue;
+
+      for (let [id, addon] of locationMap) {
+        if (!map.has(id))
+          map.set(id, addon);
+      }
+    }
+
+    return map;
+  },
+
+  /**
+   * Finds the visible add-ons from the map.
+   */
+  getVisibleAddons(addonMap) {
+    let map = new Map();
+
+    for (let [location, addons] of addonMap) {
+      for (let [id, addon] of addons) {
+        if (!addon.visible)
+          continue;
+
+        if (map.has(id)) {
+          logger.warn("Previous database listed more than one visible add-on with id " + id);
+          continue;
+        }
+
+        map.set(id, addon);
+      }
+    }
+
+    return map;
+  },
+
+  /**
+   * Called to add the metadata for an add-on in one of the install locations
+   * to the database. This can be called in three different cases. Either an
+   * add-on has been dropped into the location from outside of Firefox, or
+   * an add-on has been installed through the application, or the database
+   * has been upgraded or become corrupt and add-on data has to be reloaded
+   * into it.
+   *
+   * @param  aInstallLocation
+   *         The install location containing the add-on
+   * @param  aId
+   *         The ID of the add-on
+   * @param  aAddonState
+   *         The new state of the add-on
+   * @param  aNewAddon
+   *         The manifest for the new add-on if it has already been loaded
+   * @param  aOldAppVersion
+   *         The version of the application last run with this profile or null
+   *         if it is a new profile or the version is unknown
+   * @param  aOldPlatformVersion
+   *         The version of the platform last run with this profile or null
+   *         if it is a new profile or the version is unknown
+   * @param  aMigrateData
+   *         If during startup the database had to be upgraded this will
+   *         contain data that used to be held about this add-on
+   * @return a boolean indicating if flushing caches is required to complete
+   *         changing this add-on
+   */
+  addMetadata(aInstallLocation, aId, aAddonState, aNewAddon, aOldAppVersion,
+              aOldPlatformVersion, aMigrateData) {
+    logger.debug("New add-on " + aId + " installed in " + aInstallLocation.name);
+
+    // If we had staged data for this add-on or we aren't recovering from a
+    // corrupt database and we don't have migration data for this add-on then
+    // this must be a new install.
+    let isNewInstall = (!!aNewAddon) || (!XPIDatabase.activeBundles && !aMigrateData);
+
+    // If it's a new install and we haven't yet loaded the manifest then it
+    // must be something dropped directly into the install location
+    let isDetectedInstall = isNewInstall && !aNewAddon;
+
+    // Load the manifest if necessary and sanity check the add-on ID
+    try {
+      if (!aNewAddon) {
+        // Load the manifest from the add-on.
+        let file = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
+        file.persistentDescriptor = aAddonState.descriptor;
+        aNewAddon = syncLoadManifestFromFile(file, aInstallLocation);
+      }
+      // The add-on in the manifest should match the add-on ID.
+      if (aNewAddon.id != aId) {
+        throw new Error("Invalid addon ID: expected addon ID " + aId +
+                        ", found " + aNewAddon.id + " in manifest");
+      }
+    }
+    catch (e) {
+      logger.warn("addMetadata: Add-on " + aId + " is invalid", e);
+
+      // Remove the invalid add-on from the install location if the install
+      // location isn't locked, no restart will be necessary
+      if (aInstallLocation.isLinkedAddon(aId))
+        logger.warn("Not uninstalling invalid item because it is a proxy file");
+      else if (aInstallLocation.locked)
+        logger.warn("Could not uninstall invalid item from locked install location");
+      else
+        aInstallLocation.uninstallAddon(aId);
+      return null;
+    }
+
+    // Update the AddonInternal properties.
+    aNewAddon.installDate = aAddonState.mtime;
+    aNewAddon.updateDate = aAddonState.mtime;
+
+    // Assume that add-ons in the system add-ons install location aren't
+    // foreign and should default to enabled.
+    aNewAddon.foreignInstall = isDetectedInstall &&
+                               aInstallLocation.name != KEY_APP_SYSTEM_ADDONS &&
+                               aInstallLocation.name != KEY_APP_SYSTEM_DEFAULTS;
+
+    // appDisabled depends on whether the add-on is a foreignInstall so update
+    aNewAddon.appDisabled = !isUsableAddon(aNewAddon);
+
+    if (aMigrateData) {
+      // If there is migration data then apply it.
+      logger.debug("Migrating data from old database");
+
+      DB_MIGRATE_METADATA.forEach(function(aProp) {
+        // A theme's disabled state is determined by the selected theme
+        // preference which is read in loadManifestFromRDF
+        if (aProp == "userDisabled" && aNewAddon.type == "theme")
+          return;
+
+        if (aProp in aMigrateData)
+          aNewAddon[aProp] = aMigrateData[aProp];
+      });
+
+      // Force all non-profile add-ons to be foreignInstalls since they can't
+      // have been installed through the API
+      aNewAddon.foreignInstall |= aInstallLocation.name != KEY_APP_PROFILE;
+
+      // Some properties should only be migrated if the add-on hasn't changed.
+      // The version property isn't a perfect check for this but covers the
+      // vast majority of cases.
+      if (aMigrateData.version == aNewAddon.version) {
+        logger.debug("Migrating compatibility info");
+        if ("targetApplications" in aMigrateData)
+          aNewAddon.applyCompatibilityUpdate(aMigrateData, true);
+      }
+
+      // Since the DB schema has changed make sure softDisabled is correct
+      applyBlocklistChanges(aNewAddon, aNewAddon, aOldAppVersion,
+                            aOldPlatformVersion);
+    }
+
+    // The default theme is never a foreign install
+    if (aNewAddon.type == "theme" && aNewAddon.internalName == XPIProvider.defaultSkin)
+      aNewAddon.foreignInstall = false;
+
+    if (isDetectedInstall && aNewAddon.foreignInstall) {
+      // If the add-on is a foreign install and is in a scope where add-ons
+      // that were dropped in should default to disabled then disable it
+      let disablingScopes = Preferences.get(PREF_EM_AUTO_DISABLED_SCOPES, 0);
+      if (aInstallLocation.scope & disablingScopes) {
+        logger.warn("Disabling foreign installed add-on " + aNewAddon.id + " in "
+            + aInstallLocation.name);
+        aNewAddon.userDisabled = true;
+
+        // If we don't have an old app version then this is a new profile in
+        // which case just mark any sideloaded add-ons as already seen.
+        aNewAddon.seen = !aOldAppVersion;
+      }
+    }
+
+    return XPIDatabase.addAddonMetadata(aNewAddon, aAddonState.descriptor);
+  },
+
+  /**
+   * Called when an add-on has been removed.
+   *
+   * @param  aOldAddon
+   *         The AddonInternal as it appeared the last time the application
+   *         ran
+   * @return a boolean indicating if flushing caches is required to complete
+   *         changing this add-on
+   */
+  removeMetadata(aOldAddon) {
+    // This add-on has disappeared
+    logger.debug("Add-on " + aOldAddon.id + " removed from " + aOldAddon.location);
+    XPIDatabase.removeAddonMetadata(aOldAddon);
+  },
+
+  /**
+   * Updates an add-on's metadata and determines if a restart of the
+   * application is necessary. This is called when either the add-on's
+   * install directory path or last modified time has changed.
+   *
+   * @param  aInstallLocation
+   *         The install location containing the add-on
+   * @param  aOldAddon
+   *         The AddonInternal as it appeared the last time the application
+   *         ran
+   * @param  aAddonState
+   *         The new state of the add-on
+   * @param  aNewAddon
+   *         The manifest for the new add-on if it has already been loaded
+   * @return a boolean indicating if flushing caches is required to complete
+   *         changing this add-on
+   */
+  updateMetadata(aInstallLocation, aOldAddon, aAddonState, aNewAddon) {
+    logger.debug("Add-on " + aOldAddon.id + " modified in " + aInstallLocation.name);
+
+    try {
+      // If there isn't an updated install manifest for this add-on then load it.
+      if (!aNewAddon) {
+        let file = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
+        file.persistentDescriptor = aAddonState.descriptor;
+        aNewAddon = syncLoadManifestFromFile(file, aInstallLocation);
+        applyBlocklistChanges(aOldAddon, aNewAddon);
+
+        // Carry over any pendingUninstall state to add-ons modified directly
+        // in the profile. This is important when the attempt to remove the
+        // add-on in processPendingFileChanges failed and caused an mtime
+        // change to the add-ons files.
+        aNewAddon.pendingUninstall = aOldAddon.pendingUninstall;
+      }
+
+      // The ID in the manifest that was loaded must match the ID of the old
+      // add-on.
+      if (aNewAddon.id != aOldAddon.id)
+        throw new Error("Incorrect id in install manifest for existing add-on " + aOldAddon.id);
+    }
+    catch (e) {
+      logger.warn("updateMetadata: Add-on " + aOldAddon.id + " is invalid", e);
+      XPIDatabase.removeAddonMetadata(aOldAddon);
+      XPIStates.removeAddon(aOldAddon.location, aOldAddon.id);
+      if (!aInstallLocation.locked)
+        aInstallLocation.uninstallAddon(aOldAddon.id);
+      else
+        logger.warn("Could not uninstall invalid item from locked install location");
+
+      return null;
+    }
+
+    // Set the additional properties on the new AddonInternal
+    aNewAddon.updateDate = aAddonState.mtime;
+
+    // Update the database
+    return XPIDatabase.updateAddonMetadata(aOldAddon, aNewAddon, aAddonState.descriptor);
+  },
+
+  /**
+   * Updates an add-on's descriptor for when the add-on has moved in the
+   * filesystem but hasn't changed in any other way.
+   *
+   * @param  aInstallLocation
+   *         The install location containing the add-on
+   * @param  aOldAddon
+   *         The AddonInternal as it appeared the last time the application
+   *         ran
+   * @param  aAddonState
+   *         The new state of the add-on
+   * @return a boolean indicating if flushing caches is required to complete
+   *         changing this add-on
+   */
+  updateDescriptor(aInstallLocation, aOldAddon, aAddonState) {
+    logger.debug("Add-on " + aOldAddon.id + " moved to " + aAddonState.descriptor);
+    aOldAddon.descriptor = aAddonState.descriptor;
+    aOldAddon._sourceBundle.persistentDescriptor = aAddonState.descriptor;
+
+    return aOldAddon;
+  },
+
+  /**
+   * Called when no change has been detected for an add-on's metadata but the
+   * application has changed so compatibility may have changed.
+   *
+   * @param  aInstallLocation
+   *         The install location containing the add-on
+   * @param  aOldAddon
+   *         The AddonInternal as it appeared the last time the application
+   *         ran
+   * @param  aAddonState
+   *         The new state of the add-on
+   * @param  aOldAppVersion
+   *         The version of the application last run with this profile or null
+   *         if it is a new profile or the version is unknown
+   * @param  aOldPlatformVersion
+   *         The version of the platform last run with this profile or null
+   *         if it is a new profile or the version is unknown
+   * @param  aReloadMetadata
+   *         A boolean which indicates whether metadata should be reloaded from
+   *         the addon manifests. Default to false.
+   * @return the new addon.
+   */
+  updateCompatibility(aInstallLocation, aOldAddon, aAddonState, aOldAppVersion,
+                      aOldPlatformVersion, aReloadMetadata) {
+    logger.debug("Updating compatibility for add-on " + aOldAddon.id + " in " + aInstallLocation.name);
+
+    // If updating from a version of the app that didn't support signedState
+    // then fetch that property now
+    if (aOldAddon.signedState === undefined && ADDON_SIGNING &&
+        SIGNED_TYPES.has(aOldAddon.type)) {
+      let file = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
+      file.persistentDescriptor = aAddonState.descriptor;
+      let manifest = syncLoadManifestFromFile(file, aInstallLocation);
+      aOldAddon.signedState = manifest.signedState;
+    }
+
+    // May be updating from a version of the app that didn't support all the
+    // properties of the currently-installed add-ons.
+    if (aReloadMetadata) {
+      let file = new nsIFile()
+      file.persistentDescriptor = aAddonState.descriptor;
+      let manifest = syncLoadManifestFromFile(file, aInstallLocation);
+
+      // Avoid re-reading these properties from manifest,
+      // use existing addon instead.
+      // TODO - consider re-scanning for targetApplications.
+      let remove = ["syncGUID", "foreignInstall", "visible", "active",
+                    "userDisabled", "applyBackgroundUpdates", "sourceURI",
+                    "releaseNotesURI", "targetApplications"];
+
+      let props = PROP_JSON_FIELDS.filter(a => !remove.includes(a));
+      copyProperties(manifest, props, aOldAddon);
+    }
+
+    // This updates the addon's JSON cached data in place
+    applyBlocklistChanges(aOldAddon, aOldAddon, aOldAppVersion,
+                          aOldPlatformVersion);
+    aOldAddon.appDisabled = !isUsableAddon(aOldAddon);
+
+    return aOldAddon;
+  },
+
+  /**
+   * Compares the add-ons that are currently installed to those that were
+   * known to be installed when the application last ran and applies any
+   * changes found to the database. Also sends "startupcache-invalidate" signal to
+   * observerservice if it detects that data may have changed.
+   * Always called after XPIProviderUtils.js and extensions.json have been loaded.
+   *
+   * @param  aManifests
+   *         A dictionary of cached AddonInstalls for add-ons that have been
+   *         installed
+   * @param  aUpdateCompatibility
+   *         true to update add-ons appDisabled property when the application
+   *         version has changed
+   * @param  aOldAppVersion
+   *         The version of the application last run with this profile or null
+   *         if it is a new profile or the version is unknown
+   * @param  aOldPlatformVersion
+   *         The version of the platform last run with this profile or null
+   *         if it is a new profile or the version is unknown
+   * @param  aSchemaChange
+   *         The schema has changed and all add-on manifests should be re-read.
+   * @return a boolean indicating if a change requiring flushing the caches was
+   *         detected
+   */
+  processFileChanges(aManifests, aUpdateCompatibility, aOldAppVersion, aOldPlatformVersion,
+                     aSchemaChange) {
+    let loadedManifest = (aInstallLocation, aId) => {
+      if (!(aInstallLocation.name in aManifests))
+        return null;
+      if (!(aId in aManifests[aInstallLocation.name]))
+        return null;
+      return aManifests[aInstallLocation.name][aId];
+    };
+
+    // Add-ons loaded from the database can have an uninitialized _sourceBundle
+    // if the descriptor was invalid. Swallow that error and say they don't exist.
+    let exists = (aAddon) => {
+      try {
+        return aAddon._sourceBundle.exists();
+      }
+      catch (e) {
+        if (e.result == Cr.NS_ERROR_NOT_INITIALIZED)
+          return false;
+        throw e;
+      }
+    };
+
+    // Get the previous add-ons from the database and put them into maps by location
+    let previousAddons = new Map();
+    for (let a of XPIDatabase.getAddons()) {
+      let locationAddonMap = previousAddons.get(a.location);
+      if (!locationAddonMap) {
+        locationAddonMap = new Map();
+        previousAddons.set(a.location, locationAddonMap);
+      }
+      locationAddonMap.set(a.id, a);
+    }
+
+    // Build the list of current add-ons into similar maps. When add-ons are still
+    // present we re-use the add-on objects from the database and update their
+    // details directly
+    let currentAddons = new Map();
+    for (let installLocation of XPIProvider.installLocations) {
+      let locationAddonMap = new Map();
+      currentAddons.set(installLocation.name, locationAddonMap);
+
+      // Get all the on-disk XPI states for this location, and keep track of which
+      // ones we see in the database.
+      let states = XPIStates.getLocation(installLocation.name);
+
+      // Iterate through the add-ons installed the last time the application
+      // ran
+      let dbAddons = previousAddons.get(installLocation.name);
+      if (dbAddons) {
+        for (let [id, oldAddon] of dbAddons) {
+          // Check if the add-on is still installed
+          let xpiState = states && states.get(id);
+          if (xpiState) {
+            // Here the add-on was present in the database and on disk
+            recordAddonTelemetry(oldAddon);
+
+            // Check if the add-on has been changed outside the XPI provider
+            if (oldAddon.updateDate != xpiState.mtime) {
+              // Did time change in the wrong direction?
+              if (xpiState.mtime < oldAddon.updateDate) {
+                XPIProvider.setTelemetry(oldAddon.id, "olderFile", {
+                  name: XPIProvider._mostRecentlyModifiedFile[id],
+                  mtime: xpiState.mtime,
+                  oldtime: oldAddon.updateDate
+                });
+              } else {
+                XPIProvider.setTelemetry(oldAddon.id, "modifiedFile",
+                                         XPIProvider._mostRecentlyModifiedFile[id]);
+              }
+            }
+
+            // The add-on has changed if the modification time has changed, if
+            // we have an updated manifest for it, or if the schema version has
+            // changed.
+            //
+            // Also reload the metadata for add-ons in the application directory
+            // when the application version has changed.
+            let newAddon = loadedManifest(installLocation, id);
+            if (newAddon || oldAddon.updateDate != xpiState.mtime ||
+                (aUpdateCompatibility && (installLocation.name == KEY_APP_GLOBAL ||
+                                          installLocation.name == KEY_APP_SYSTEM_DEFAULTS))) {
+              newAddon = this.updateMetadata(installLocation, oldAddon, xpiState, newAddon);
+            }
+            else if (oldAddon.descriptor != xpiState.descriptor) {
+              newAddon = this.updateDescriptor(installLocation, oldAddon, xpiState);
+            }
+            // Check compatility when the application version and/or schema
+            // version has changed. A schema change also reloads metadata from
+            // the manifests.
+            else if (aUpdateCompatibility || aSchemaChange) {
+              newAddon = this.updateCompatibility(installLocation, oldAddon, xpiState,
+                                                  aOldAppVersion, aOldPlatformVersion,
+                                                  aSchemaChange);
+            }
+            else {
+              // No change
+              newAddon = oldAddon;
+            }
+
+            if (newAddon)
+              locationAddonMap.set(newAddon.id, newAddon);
+          }
+          else {
+            // The add-on is in the DB, but not in xpiState (and thus not on disk).
+            this.removeMetadata(oldAddon);
+          }
+        }
+      }
+
+      // Any add-on in our current location that we haven't seen needs to
+      // be added to the database.
+      // Get the migration data for this install location so we can include that as
+      // we add, in case this is a database upgrade or rebuild.
+      let locMigrateData = {};
+      if (XPIDatabase.migrateData && installLocation.name in XPIDatabase.migrateData)
+        locMigrateData = XPIDatabase.migrateData[installLocation.name];
+
+      if (states) {
+        for (let [id, xpiState] of states) {
+          if (locationAddonMap.has(id))
+            continue;
+          let migrateData = id in locMigrateData ? locMigrateData[id] : null;
+          let newAddon = loadedManifest(installLocation, id);
+          let addon = this.addMetadata(installLocation, id, xpiState, newAddon,
+                                       aOldAppVersion, aOldPlatformVersion, migrateData);
+          if (addon)
+            locationAddonMap.set(addon.id, addon);
+        }
+      }
+    }
+
+    // previousAddons may contain locations where the database contains add-ons
+    // but the browser is no longer configured to use that location. The metadata
+    // for those add-ons must be removed from the database.
+    for (let [locationName, addons] of previousAddons) {
+      if (!currentAddons.has(locationName)) {
+        for (let [id, oldAddon] of addons)
+          this.removeMetadata(oldAddon);
+      }
+    }
+
+    // Validate the updated system add-ons
+    let systemAddonLocation = XPIProvider.installLocationsByName[KEY_APP_SYSTEM_ADDONS];
+    let addons = currentAddons.get(KEY_APP_SYSTEM_ADDONS) || new Map();
+
+    let hideLocation;
+
+    if (!systemAddonLocation.isValid(addons)) {
+      // Hide the system add-on updates if any are invalid.
+      logger.info("One or more updated system add-ons invalid, falling back to defaults.");
+      hideLocation = KEY_APP_SYSTEM_ADDONS;
+    }
+
+    let previousVisible = this.getVisibleAddons(previousAddons);
+    let currentVisible = this.flattenByID(currentAddons, hideLocation);
+    let sawActiveTheme = false;
+    XPIProvider.bootstrappedAddons = {};
+
+    // Pass over the new set of visible add-ons, record any changes that occured
+    // during startup and call bootstrap install/uninstall scripts as necessary
+    for (let [id, currentAddon] of currentVisible) {
+      let previousAddon = previousVisible.get(id);
+
+      // Note if any visible add-on is not in the application install location
+      if (currentAddon._installLocation.name != KEY_APP_GLOBAL)
+        XPIProvider.allAppGlobal = false;
+
+      let isActive = !currentAddon.disabled;
+      let wasActive = previousAddon ? previousAddon.active : currentAddon.active
+
+      if (!previousAddon) {
+        // If we had a manifest for this add-on it was a staged install and
+        // so wasn't something recovered from a corrupt database
+        let wasStaged = !!loadedManifest(currentAddon._installLocation, id);
+
+        // We might be recovering from a corrupt database, if so use the
+        // list of known active add-ons to update the new add-on
+        if (!wasStaged && XPIDatabase.activeBundles) {
+          // For themes we know which is active by the current skin setting
+          if (currentAddon.type == "theme")
+            isActive = currentAddon.internalName == XPIProvider.currentSkin;
+          else
+            isActive = XPIDatabase.activeBundles.indexOf(currentAddon.descriptor) != -1;
+
+          // If the add-on wasn't active and it isn't already disabled in some way
+          // then it was probably either softDisabled or userDisabled
+          if (!isActive && !currentAddon.disabled) {
+            // If the add-on is softblocked then assume it is softDisabled
+            if (currentAddon.blocklistState == Blocklist.STATE_SOFTBLOCKED)
+              currentAddon.softDisabled = true;
+            else
+              currentAddon.userDisabled = true;
+          }
+        }
+        else {
+          // This is a new install
+          if (currentAddon.foreignInstall)
+            AddonManagerPrivate.addStartupChange(AddonManager.STARTUP_CHANGE_INSTALLED, id);
+
+          if (currentAddon.bootstrap) {
+            AddonManagerPrivate.addStartupChange(AddonManager.STARTUP_CHANGE_INSTALLED, id);
+            // Visible bootstrapped add-ons need to have their install method called
+            XPIProvider.callBootstrapMethod(currentAddon, currentAddon._sourceBundle,
+                                            "install", BOOTSTRAP_REASONS.ADDON_INSTALL);
+            if (!isActive)
+              XPIProvider.unloadBootstrapScope(currentAddon.id);
+          }
+        }
+      }
+      else {
+        if (previousAddon !== currentAddon) {
+          // This is an add-on that has changed, either the metadata was reloaded
+          // or the version in a different location has become visible
+          AddonManagerPrivate.addStartupChange(AddonManager.STARTUP_CHANGE_CHANGED, id);
+
+          let installReason = Services.vc.compare(previousAddon.version, currentAddon.version) < 0 ?
+                              BOOTSTRAP_REASONS.ADDON_UPGRADE :
+                              BOOTSTRAP_REASONS.ADDON_DOWNGRADE;
+
+          // If the previous add-on was in a different path, bootstrapped
+          // and still exists then call its uninstall method.
+          if (previousAddon.bootstrap && previousAddon._installLocation &&
+              exists(previousAddon) &&
+              currentAddon._sourceBundle.path != previousAddon._sourceBundle.path) {
+
+            XPIProvider.callBootstrapMethod(previousAddon, previousAddon._sourceBundle,
+                                            "uninstall", installReason,
+                                            { newVersion: currentAddon.version });
+            XPIProvider.unloadBootstrapScope(previousAddon.id);
+          }
+
+          // Make sure to flush the cache when an old add-on has gone away
+          flushChromeCaches();
+
+          if (currentAddon.bootstrap) {
+            // Visible bootstrapped add-ons need to have their install method called
+            let file = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
+            file.persistentDescriptor = currentAddon._sourceBundle.persistentDescriptor;
+            XPIProvider.callBootstrapMethod(currentAddon, file,
+                                            "install", installReason,
+                                            { oldVersion: previousAddon.version });
+            if (currentAddon.disabled)
+              XPIProvider.unloadBootstrapScope(currentAddon.id);
+          }
+        }
+
+        if (isActive != wasActive) {
+          let change = isActive ? AddonManager.STARTUP_CHANGE_ENABLED
+                                : AddonManager.STARTUP_CHANGE_DISABLED;
+          AddonManagerPrivate.addStartupChange(change, id);
+        }
+      }
+
+      XPIDatabase.makeAddonVisible(currentAddon);
+      currentAddon.active = isActive;
+
+      // Make sure the bootstrap information is up to date for this ID
+      if (currentAddon.bootstrap && currentAddon.active) {
+        XPIProvider.bootstrappedAddons[id] = {
+          version: currentAddon.version,
+          type: currentAddon.type,
+          descriptor: currentAddon._sourceBundle.persistentDescriptor,
+          multiprocessCompatible: currentAddon.multiprocessCompatible,
+          runInSafeMode: canRunInSafeMode(currentAddon),
+          dependencies: currentAddon.dependencies,
+          hasEmbeddedWebExtension: currentAddon.hasEmbeddedWebExtension,
+        };
+      }
+
+      if (currentAddon.active && currentAddon.internalName == XPIProvider.selectedSkin)
+        sawActiveTheme = true;
+    }
+
+    // Pass over the set of previously visible add-ons that have now gone away
+    // and record the change.
+    for (let [id, previousAddon] of previousVisible) {
+      if (currentVisible.has(id))
+        continue;
+
+      // This add-on vanished
+
+      // If the previous add-on was bootstrapped and still exists then call its
+      // uninstall method.
+      if (previousAddon.bootstrap && exists(previousAddon)) {
+        XPIProvider.callBootstrapMethod(previousAddon, previousAddon._sourceBundle,
+                                        "uninstall", BOOTSTRAP_REASONS.ADDON_UNINSTALL);
+        XPIProvider.unloadBootstrapScope(previousAddon.id);
+      }
+      AddonManagerPrivate.addStartupChange(AddonManager.STARTUP_CHANGE_UNINSTALLED, id);
+
+      // Make sure to flush the cache when an old add-on has gone away
+      flushChromeCaches();
+    }
+
+    // Make sure add-ons from hidden locations are marked invisible and inactive
+    let locationAddonMap = currentAddons.get(hideLocation);
+    if (locationAddonMap) {
+      for (let addon of locationAddonMap.values()) {
+        addon.visible = false;
+        addon.active = false;
+      }
+    }
+
+    // If a custom theme is selected and it wasn't seen in the new list of
+    // active add-ons then enable the default theme
+    if (XPIProvider.selectedSkin != XPIProvider.defaultSkin && !sawActiveTheme) {
+      logger.info("Didn't see selected skin " + XPIProvider.selectedSkin);
+      XPIProvider.enableDefaultTheme();
+    }
+
+    // Finally update XPIStates to match everything
+    for (let [locationName, locationAddonMap] of currentAddons) {
+      for (let [id, addon] of locationAddonMap) {
+        let xpiState = XPIStates.getAddon(locationName, id);
+        xpiState.syncWithDB(addon);
+      }
+    }
+    XPIStates.save();
+
+    XPIProvider.persistBootstrappedAddons();
+
+    // Clear out any cached migration data.
+    XPIDatabase.migrateData = null;
+    XPIDatabase.saveChanges();
+
+    return true;
+  },
+}