Bug 1407700 Part1: Revise CoalescedInputData interfaces. r=smaug.

MozReview-Commit-ID: 75AsFBM4qr

dom/ipc/CoalescedInputData.h

@@ -29,11 +29,6 @@ public:
   {
   }
 
-  void Reset()
-  {
-    mCoalescedInputEvent = nullptr;
-  }
-
   bool IsEmpty()
   {
     return !mCoalescedInputEvent;
@@ -43,9 +38,9 @@ public:
                    const ScrollableLayerGuid& aGuid,
                    const uint64_t& aInputBlockId);
 
-  const InputEventType* GetCoalescedEvent()
+  UniquePtr<InputEventType> TakeCoalescedEvent()
   {
-    return mCoalescedInputEvent.get();
+    return Move(mCoalescedInputEvent);
   }
 
   ScrollableLayerGuid GetScrollableLayerGuid()

dom/ipc/TabChild.cpp

@@ -1601,14 +1601,13 @@ TabChild::MaybeDispatchCoalescedMouseMoveEvents()
     if (!data || data->IsEmpty()) {
       continue;
     }
-    const WidgetMouseEvent* event = data->GetCoalescedEvent();
+    UniquePtr<WidgetMouseEvent> event = data->TakeCoalescedEvent();
     MOZ_ASSERT(event);
     // Dispatch the coalesced mousemove event. Using RecvRealMouseButtonEvent to
     // bypass the coalesce handling in RecvRealMouseMoveEvent.
     RecvRealMouseButtonEvent(*event,
                              data->GetScrollableLayerGuid(),
                              data->GetInputBlockId());
-    data->Reset();
   }
   if (mCoalescedMouseEventFlusher) {
     mCoalescedMouseEventFlusher->RemoveObserver();
@@ -1779,13 +1778,12 @@ TabChild::MaybeDispatchCoalescedWheelEvent()
   if (mCoalescedWheelData.IsEmpty()) {
     return;
   }
-  const WidgetWheelEvent* wheelEvent =
-    mCoalescedWheelData.GetCoalescedEvent();
+  UniquePtr<WidgetWheelEvent> wheelEvent =
+    mCoalescedWheelData.TakeCoalescedEvent();
   MOZ_ASSERT(wheelEvent);
   DispatchWheelEvent(*wheelEvent,
                      mCoalescedWheelData.GetScrollableLayerGuid(),
                      mCoalescedWheelData.GetInputBlockId());
-  mCoalescedWheelData.Reset();
 }
 
 void