Bug 1013412 - End wheel transactions as soon as possible if content is doing a prevent-default. r=dvander

gfx/layers/apz/src/InputBlockState.cpp

@@ -181,6 +181,15 @@ WheelBlockState::WheelBlockState(const nsRefPtr<AsyncPanZoomController>& aTarget
   }
 }
 
+bool
+WheelBlockState::SetContentResponse(bool aPreventDefault)
+{
+  if (aPreventDefault) {
+    EndTransaction();
+  }
+  return CancelableBlockState::SetContentResponse(aPreventDefault);
+}
+
 bool
 WheelBlockState::SetConfirmedTargetApzc(const nsRefPtr<AsyncPanZoomController>& aTargetApzc)
 {

gfx/layers/apz/src/InputBlockState.h

@@ -92,7 +92,7 @@ public:
    * @return false if this block has already received a response from
    *         web content, true if not.
    */
-  bool SetContentResponse(bool aPreventDefault);
+  virtual bool SetContentResponse(bool aPreventDefault);
 
   /**
    * Record that content didn't respond in time.
@@ -161,6 +161,7 @@ public:
                   bool aTargetConfirmed,
                   const ScrollWheelInput& aEvent);
 
+  bool SetContentResponse(bool aPreventDefault) override;
   bool IsReadyForHandling() const override;
   bool HasEvents() const override;
   void DropEvents() override;