1 files changed, 13 insertions, 1 deletions
diff --git a/layout/style/nsCSSParser.h b/layout/style/nsCSSParser.h
index 37cd325f20..e3d526659d 100644
--- a/layout/style/nsCSSParser.h
+++ b/layout/style/nsCSSParser.h
@@ -34,6 +34,12 @@ namespace css {
 class Rule;
 class Declaration;
 class StyleRule;
+
+enum class SupportsParsingSettings {
+  Normal,
+  ImpliedParentheses
+};
+
 } // namespace css
 } // namespace mozilla
 
@@ -257,11 +263,17 @@ public:
   /**
    * Parse an @supports condition and returns the result of evaluating the
    * condition.
+   *
+   * The one-argument CSS.supports() allows for providing an @supports condition
+   * without parentheses, i.e. the parentheses are "implied". In such a case,
+   * aSettings can be set to ImpliedParentheses.
    */
   bool EvaluateSupportsCondition(const nsAString& aCondition,
                                  nsIURI* aDocURL,
                                  nsIURI* aBaseURL,
-                                 nsIPrincipal* aDocPrincipal);
+                                 nsIPrincipal* aDocPrincipal,
+                                 mozilla::css::SupportsParsingSettings aSettings
+                                   = mozilla::css::SupportsParsingSettings::Normal);
 
   typedef void (*VariableEnumFunc)(const nsAString&, void*);