Backed out changeset 71c0f51e780a (bug 1924803) for causing valgrind failures at WantMutationEvents. CLOSED TREE

dom/base/Document.h

@@ -3567,6 +3567,8 @@ class Document : public nsINode,
   }
   void SetDevToolsWatchingDOMMutations(bool aValue);
 
+  void MaybeWarnAboutZoom();
+
   // https://drafts.csswg.org/cssom-view/#evaluate-media-queries-and-report-changes
   void EvaluateMediaQueriesAndReportChanges(bool aRecurse);
 
@@ -4887,6 +4889,12 @@ class Document : public nsINode,
   // eDesignMode or eContentEditable.
   bool mHasBeenEditable : 1;
 
+  // Whether we've warned about the CSS zoom property.
+  //
+  // We don't use the general deprecated operation mechanism for this because we
+  // also record this as a `CountedUnknownProperty`.
+  bool mHasWarnedAboutZoom : 1;
+
   // While we're handling an execCommand call by web app, set
   // to true.
   bool mIsRunningExecCommandByContent : 1;