Bug 1267718 - Add a nsPIDOMWindow::GetScriptableParentOrNull method. r=bz

MozReview-Commit-ID: 9L33Wq0fBF6

dom/audiochannel/AudioChannelService.cpp

@@ -387,8 +387,8 @@ AudioChannelService::GetState(nsPIDOMWindowOuter* aWindow, uint32_t aAudioChanne
     // TODO : distiguish between suspend and mute, it would be done in bug1242874.
     *aMuted = *aMuted || window->GetMediaSuspended() || window->GetAudioMuted();
 
-    nsCOMPtr<nsPIDOMWindowOuter> win = window->GetScriptableParent();
+    nsCOMPtr<nsPIDOMWindowOuter> win = window->GetScriptableParentOrNull();
-    if (window == win) {
+    if (!win) {
       break;
     }
 

dom/base/nsGlobalWindow.cpp

@@ -3658,8 +3658,8 @@ nsPIDOMWindowInner::CreatePerformanceObjectIfNeeded()
     // If we are dealing with an iframe, we will need the parent's performance
     // object (so we can add the iframe as a resource of that page).
     nsPerformance* parentPerformance = nullptr;
-    nsCOMPtr<nsPIDOMWindowOuter> parentWindow = GetScriptableParent();
+    nsCOMPtr<nsPIDOMWindowOuter> parentWindow = GetScriptableParentOrNull();
-    if (GetOuterWindow() != parentWindow) {
+    if (parentWindow) {
       nsPIDOMWindowInner* parentInnerWindow = nullptr;
       if (parentWindow) {
         parentInnerWindow = parentWindow->GetCurrentInnerWindow();
@@ -3878,6 +3878,19 @@ nsGlobalWindow::GetScriptableParent()
   return parent.get();
 }
 
+/**
+ * Behavies identically to GetScriptableParent extept that it returns null
+ * if GetScriptableParent would return this window.
+ */
+nsPIDOMWindowOuter*
+nsGlobalWindow::GetScriptableParentOrNull()
+{
+  FORWARD_TO_OUTER(GetScriptableParentOrNull, (), nullptr);
+
+  nsPIDOMWindowOuter* parent = GetScriptableParent();
+  return (Cast(parent) == this) ? nullptr : parent;
+}
+
 /**
  * nsPIDOMWindow::GetParent (when called from C++) is just a wrapper around
  * GetRealParent.

dom/base/nsGlobalWindow.h

@@ -896,6 +896,7 @@ public:
   already_AddRefed<nsPIDOMWindowOuter> GetParent(mozilla::ErrorResult& aError);
   already_AddRefed<nsPIDOMWindowOuter> GetParent() override;
   nsPIDOMWindowOuter* GetScriptableParent() override;
+  nsPIDOMWindowOuter* GetScriptableParentOrNull() override;
   mozilla::dom::Element* GetFrameElementOuter();
   mozilla::dom::Element* GetFrameElement(mozilla::ErrorResult& aError);
   already_AddRefed<nsIDOMElement> GetFrameElement() override;

dom/base/nsPIDOMWindow.h

@@ -118,6 +118,12 @@ public:
   virtual nsPIDOMWindowOuter* GetScriptableParent() = 0;
   virtual already_AddRefed<nsPIWindowRoot> GetTopWindowRoot() = 0;
 
+  /**
+   * Behavies identically to GetScriptableParent extept that it returns null
+   * if GetScriptableParent would return this window.
+   */
+  virtual nsPIDOMWindowOuter* GetScriptableParentOrNull() = 0;
+
   // Inner windows only.
   virtual nsresult RegisterIdleObserver(nsIIdleObserver* aIdleObserver) = 0;
   virtual nsresult UnregisterIdleObserver(nsIIdleObserver* aIdleObserver) = 0;

dom/ipc/TabParent.cpp

@@ -3275,8 +3275,8 @@ TabParent::AudioChannelChangeNotification(nsPIDOMWindowOuter* aWindow,
       break;
     }
 
-    nsCOMPtr<nsPIDOMWindowOuter> win = window->GetScriptableParent();
+    nsCOMPtr<nsPIDOMWindowOuter> win = window->GetScriptableParentOrNull();
-    if (window == win) {
+    if (!win) {
       break;
     }