Bug 1444580: Devirtualize the visibility state stuff. r=smaug

Also rename GetVisibilityState to ComputeVisibilityState, since that's what it
does, the getter is VisibilityState.

MozReview-Commit-ID: 9qfKvUmO0dW

dom/base/nsDocument.cpp

@@ -4971,7 +4971,7 @@ nsDocument::SetScriptGlobalObject(nsIScriptGlobalObject *aScriptGlobalObject)
   // doing the initial document load and don't want to fire the event for this
   // change.
   dom::VisibilityState oldState = mVisibilityState;
-  mVisibilityState = GetVisibilityState();
+  mVisibilityState = ComputeVisibilityState();
   // When the visibility is changed, notify it to observers.
   // Some observers need the notification, for example HTMLMediaElement uses
   // it to update internal media resource allocation.
@@ -11816,10 +11816,10 @@ nsIDocument::UnlockPointer(nsIDocument* aDoc)
 }
 
 void
-nsDocument::UpdateVisibilityState()
+nsIDocument::UpdateVisibilityState()
 {
   dom::VisibilityState oldState = mVisibilityState;
-  mVisibilityState = GetVisibilityState();
+  mVisibilityState = ComputeVisibilityState();
   if (oldState != mVisibilityState) {
     nsContentUtils::DispatchTrustedEvent(this, static_cast<nsIDocument*>(this),
                                          NS_LITERAL_STRING("visibilitychange"),
@@ -11834,7 +11834,7 @@ nsDocument::UpdateVisibilityState()
 }
 
 VisibilityState
-nsDocument::GetVisibilityState() const
+nsIDocument::ComputeVisibilityState() const
 {
   // We have to check a few pieces of information here:
   // 1)  Are we in bfcache (!IsVisible())?  If so, nothing else matters.
@@ -11851,18 +11851,18 @@ nsDocument::GetVisibilityState() const
   return dom::VisibilityState::Visible;
 }
 
-/* virtual */ void
-nsDocument::PostVisibilityUpdateEvent()
+void
+nsIDocument::PostVisibilityUpdateEvent()
 {
   nsCOMPtr<nsIRunnable> event =
-    NewRunnableMethod("nsDocument::UpdateVisibilityState",
+    NewRunnableMethod("nsIDocument::UpdateVisibilityState",
                       this,
-                      &nsDocument::UpdateVisibilityState);
+                      &nsIDocument::UpdateVisibilityState);
   Dispatch(TaskCategory::Other, event.forget());
 }
 
 void
-nsDocument::MaybeActiveMediaComponents()
+nsIDocument::MaybeActiveMediaComponents()
 {
   if (!mWindow) {
     return;

dom/base/nsDocument.h

@@ -747,16 +747,6 @@ public:
   void SetOrientationPendingPromise(mozilla::dom::Promise* aPromise) override;
   mozilla::dom::Promise* GetOrientationPendingPromise() const override;
 
-  // This method may fire a DOM event; if it does so it will happen
-  // synchronously.
-  void UpdateVisibilityState();
-  // Posts an event to call UpdateVisibilityState
-  virtual void PostVisibilityUpdateEvent() override;
-
-  // Since we wouldn't automatically play media from non-visited page, we need
-  // to notify window when the page was first visited.
-  void MaybeActiveMediaComponents();
-
   virtual void DocAddSizeOfExcludingThis(nsWindowSizes& aWindowSizes) const override;
   // DocAddSizeOfIncludingThis is inherited from nsIDocument.
 
@@ -901,8 +891,6 @@ public:
   nsCOMPtr<nsIContent> mFirstBaseNodeWithHref;
 private:
   friend class nsUnblockOnloadEvent;
-  // Recomputes the visibility state but doesn't set the new value.
-  mozilla::dom::VisibilityState GetVisibilityState() const;
 
   void PostUnblockOnloadEvent();
   void DoUnblockOnload();

dom/base/nsIDocument.h

@@ -2822,7 +2822,8 @@ public:
                      const char16_t **aParams = nullptr,
                      uint32_t aParamsLength = 0) const;
 
-  virtual void PostVisibilityUpdateEvent() = 0;
+  // Posts an event to call UpdateVisibilityState
+  void PostVisibilityUpdateEvent();
 
   bool IsSyntheticDocument() const { return mIsSyntheticDocument; }
 
@@ -3332,6 +3333,17 @@ protected:
 
   void RecordNavigationTiming(ReadyState aReadyState);
 
+  // This method may fire a DOM event; if it does so it will happen
+  // synchronously.
+  void UpdateVisibilityState();
+
+  // Recomputes the visibility state but doesn't set the new value.
+  mozilla::dom::VisibilityState ComputeVisibilityState() const;
+
+  // Since we wouldn't automatically play media from non-visited page, we need
+  // to notify window when the page was first visited.
+  void MaybeActiveMediaComponents();
+
   bool GetUseCounter(mozilla::UseCounter aUseCounter)
   {
     return mUseCounters[aUseCounter];