Bug 1320753 - Stop using already_AddRefed for EventTargetFor (r=ehsan)

MozReview-Commit-ID: ECy1jlQ7qne

dom/base/Dispatcher.cpp

@@ -29,11 +29,11 @@ DispatcherTrait::Dispatch(const char* aName,
   }
 }
 
-already_AddRefed<nsIEventTarget>
+nsIEventTarget*
 DispatcherTrait::EventTargetFor(TaskCategory aCategory) const
 {
   nsCOMPtr<nsIEventTarget> main = do_GetMainThread();
-  return main.forget();
+  return main;
 }
 
 namespace {

dom/base/Dispatcher.h

@@ -56,8 +56,7 @@ public:
   // This method may or may not be safe off of the main thread. For nsIDocument
   // it is safe. For nsIGlobalWindow it is not safe. The nsIEventTarget can
   // always be used off the main thread.
-  virtual already_AddRefed<nsIEventTarget>
-  EventTargetFor(TaskCategory aCategory) const;
+  virtual nsIEventTarget* EventTargetFor(TaskCategory aCategory) const;
 };
 
 // Base class for DocGroup and TabGroup.
@@ -70,8 +69,7 @@ public:
 
   // This method is always safe to call off the main thread. The nsIEventTarget
   // can always be used off the main thread.
-  virtual already_AddRefed<nsIEventTarget>
-  EventTargetFor(TaskCategory aCategory) const = 0;
+  virtual nsIEventTarget* EventTargetFor(TaskCategory aCategory) const = 0;
 
   // These methods perform a safe cast. They return null if |this| is not of the
   // requested type.

dom/base/DocGroup.cpp

@@ -63,7 +63,7 @@ DocGroup::Dispatch(const char* aName,
   return mTabGroup->Dispatch(aName, aCategory, Move(aRunnable));
 }
 
-already_AddRefed<nsIEventTarget>
+nsIEventTarget*
 DocGroup::EventTargetFor(TaskCategory aCategory) const
 {
   return mTabGroup->EventTargetFor(aCategory);

dom/base/DocGroup.h

@@ -69,8 +69,7 @@ public:
                             TaskCategory aCategory,
                             already_AddRefed<nsIRunnable>&& aRunnable) override;
 
-  virtual already_AddRefed<nsIEventTarget>
-  EventTargetFor(TaskCategory aCategory) const override;
+  virtual nsIEventTarget* EventTargetFor(TaskCategory aCategory) const override;
 
 private:
   DocGroup(TabGroup* aTabGroup, const nsACString& aKey);

dom/base/TabGroup.cpp

@@ -255,12 +255,11 @@ TabGroup::Dispatch(const char* aName,
   }
 }
 
-already_AddRefed<nsIEventTarget>
+nsIEventTarget*
 TabGroup::EventTargetFor(TaskCategory aCategory) const
 {
   MOZ_RELEASE_ASSERT(!mLastWindowLeft);
-  nsCOMPtr<nsIEventTarget> target = mEventTargets[size_t(aCategory)];
-  return target.forget();
+  return mEventTargets[size_t(aCategory)];
 }
 
 }

dom/base/TabGroup.h

@@ -13,6 +13,7 @@
 #include "nsTHashtable.h"
 #include "nsString.h"
 
+#include "mozilla/Atomics.h"
 #include "mozilla/dom/Dispatcher.h"
 #include "mozilla/RefPtr.h"
 
@@ -114,12 +115,14 @@ public:
   ThrottledEventQueue*
   GetThrottledEventQueue() const;
 
+  // This method is always safe to call off the main thread.
   virtual nsresult Dispatch(const char* aName,
                             TaskCategory aCategory,
                             already_AddRefed<nsIRunnable>&& aRunnable) override;
 
-  virtual already_AddRefed<nsIEventTarget>
-  EventTargetFor(TaskCategory aCategory) const override;
+  // This method is always safe to call off the main thread. The nsIEventTarget
+  // can always be used off the main thread.
+  virtual nsIEventTarget* EventTargetFor(TaskCategory aCategory) const override;
 
   TabGroup* AsTabGroup() override { return this; }
 
@@ -128,7 +131,7 @@ private:
 
   ~TabGroup();
   DocGroupMap mDocGroups;
-  bool mLastWindowLeft;
+  Atomic<bool> mLastWindowLeft;
   nsTArray<nsPIDOMWindowOuter*> mWindows;
   bool mThrottledQueuesInitialized;
   RefPtr<ThrottledEventQueue> mThrottledEventQueue;

dom/base/nsDocument.cpp

@@ -2891,7 +2891,7 @@ nsIDocument::Dispatch(const char* aName,
   return DispatcherTrait::Dispatch(aName, aCategory, Move(aRunnable));
 }
 
-already_AddRefed<nsIEventTarget>
+nsIEventTarget*
 nsIDocument::EventTargetFor(TaskCategory aCategory) const
 {
   if (mDocGroup) {

dom/base/nsGlobalWindow.cpp

@@ -14266,7 +14266,7 @@ nsGlobalWindow::Dispatch(const char* aName,
   return DispatcherTrait::Dispatch(aName, aCategory, Move(aRunnable));
 }
 
-already_AddRefed<nsIEventTarget>
+nsIEventTarget*
 nsGlobalWindow::EventTargetFor(TaskCategory aCategory) const
 {
   MOZ_RELEASE_ASSERT(NS_IsMainThread());

dom/base/nsGlobalWindow.h

@@ -1770,7 +1770,7 @@ public:
                             mozilla::dom::TaskCategory aCategory,
                             already_AddRefed<nsIRunnable>&& aRunnable) override;
 
-  virtual already_AddRefed<nsIEventTarget>
+  virtual nsIEventTarget*
   EventTargetFor(mozilla::dom::TaskCategory aCategory) const override;
 
 protected:

dom/base/nsIDocument.h

@@ -2872,7 +2872,7 @@ public:
                             mozilla::dom::TaskCategory aCategory,
                             already_AddRefed<nsIRunnable>&& aRunnable) override;
 
-  virtual already_AddRefed<nsIEventTarget>
+  virtual nsIEventTarget*
   EventTargetFor(mozilla::dom::TaskCategory aCategory) const override;
 
   // The URLs passed to these functions should match what