Use mDestroyRefCount in a more straightforward way.

3 files changed, 10 insertions, 9 deletions

diff --git a/layout/base/nsDocumentViewer.cpp b/layout/base/nsDocumentViewer.cpp
index 65649504c..157db20b5 100644
--- a/layout/base/nsDocumentViewer.cpp
+++ b/layout/base/nsDocumentViewer.cpp
@@ -1617,7 +1617,6 @@ nsDocumentViewer::Destroy()
   // We also keep the viewer from being cached in session history, since
   // we require all documents there to be sanitized.
   if (mDestroyRefCount != 0) {
-    --mDestroyRefCount;
     return NS_OK;
   }
 
@@ -4305,6 +4304,12 @@ nsDocumentViewer::IncrementDestroyRefCount()
   ++mDestroyRefCount;
 }
 
+void
+nsDocumentViewer::DecrementDestroyRefCount()
+{
+  --mDestroyRefCount;
+}
+
 //------------------------------------------------------------
 
 #if defined(NS_PRINTING) && defined(NS_PRINT_PREVIEW)
diff --git a/layout/base/nsIDocumentViewerPrint.h b/layout/base/nsIDocumentViewerPrint.h
index 5ddb516e4..3ca625162 100644
--- a/layout/base/nsIDocumentViewerPrint.h
+++ b/layout/base/nsIDocumentViewerPrint.h
@@ -40,6 +40,7 @@ public:
   virtual nsresult CreateStyleSet(nsIDocument* aDocument, nsStyleSet** aStyleSet) = 0;
 
   virtual void IncrementDestroyRefCount() = 0;
+  virtual void DecrementDestroyRefCount() = 0;
 
   virtual void ReturnToGalleyPresentation() = 0;
 
@@ -74,6 +75,7 @@ NS_DEFINE_STATIC_IID_ACCESSOR(nsIDocumentViewerPrint,
   virtual bool     GetIsPrintPreview() override; \
   virtual nsresult CreateStyleSet(nsIDocument* aDocument, nsStyleSet** aStyleSet) override; \
   virtual void     IncrementDestroyRefCount() override; \
+  virtual void     DecrementDestroyRefCount() override; \
   virtual void     ReturnToGalleyPresentation() override; \
   virtual void     OnDonePrinting() override; \
   virtual bool     IsInitializedForPrintPreview() override; \
diff --git a/layout/printing/nsPagePrintTimer.cpp b/layout/printing/nsPagePrintTimer.cpp
index 01d44d86d..9b897092e 100644
--- a/layout/printing/nsPagePrintTimer.cpp
+++ b/layout/printing/nsPagePrintTimer.cpp
@@ -12,14 +12,8 @@ NS_IMPL_ISUPPORTS_INHERITED(nsPagePrintTimer, nsRunnable, nsITimerCallback)
 
 nsPagePrintTimer::~nsPagePrintTimer()
 {
-  // "Destroy" the document viewer; this normally doesn't actually
-  // destroy it because of the IncrementDestroyRefCount call below
-  // XXX This is messy; the document viewer should use a single approach
-  // to keep itself alive during printing
-  nsCOMPtr<nsIContentViewer> cv(do_QueryInterface(mDocViewerPrint));
-  if (cv) {
-    cv->Destroy();
-  }
+  // This matches IncrementDestroyRefCount() in the ctor.
+  mDocViewerPrint->DecrementDestroyRefCount();
 }
 
 nsresult