Pass implementation object to supplemental classes by reference

Source/core/page/scrolling/ScrollingCoordinator.cpp

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 781 matching lines @@
 
     accumulateDocumentTouchEventTargetRects(rects, document);
 }
 
 unsigned ScrollingCoordinator::computeCurrentWheelEventHandlerCount()
 {
     unsigned wheelEventHandlerCount = 0;
 
     for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
         if (frame->document())
-            wheelEventHandlerCount += WheelController::from(frame->document())->wheelEventHandlerCount();
+            wheelEventHandlerCount += WheelController::from(*frame->document())->wheelEventHandlerCount();
     }
 
     return wheelEventHandlerCount;
 }
 
 void ScrollingCoordinator::frameViewWheelEventHandlerCountChanged(FrameView* frameView)
 {
     ASSERT(isMainThread());
     ASSERT(m_page);
 
@@ skipping 153 matching lines @@
     bool frameIsScrollable = frameView && frameView->isScrollable();
     if (frameIsScrollable != m_wasFrameScrollable)
         return true;
 
     if (WebLayer* scrollLayer = frameView ? scrollingWebLayerForScrollableArea(frameView) : 0)
         return blink::WebSize(frameView->contentsSize()) != scrollLayer->bounds();
     return false;
 }
 
 } // namespace WebCore