Pass implementation object to supplemental classes by reference

Source/core/rendering/RenderLayerCompositor.cpp

 /*
  * Copyright (C) 2009, 2010 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 304 matching lines @@
         (*it)->updateHasUnclippedDescendant();
 
     const FrameView::ScrollableAreaSet* scrollableAreas = m_renderView->frameView()->scrollableAreas();
     if (!scrollableAreas)
         return;
 
     for (FrameView::ScrollableAreaSet::iterator it = scrollableAreas->begin(); it != scrollableAreas->end(); ++it)
         (*it)->updateNeedsCompositedScrolling();
 }
 
-static RenderVideo* findFullscreenVideoRenderer(Document* document)
+static RenderVideo* findFullscreenVideoRenderer(Document& document)
 {
     Element* fullscreenElement = FullscreenElementStack::currentFullScreenElementFrom(document);
     while (fullscreenElement && fullscreenElement->isFrameOwnerElement()) {
-        document = toHTMLFrameOwnerElement(fullscreenElement)->contentDocument();
-        if (!document)
+        Document* contentDocument = toHTMLFrameOwnerElement(fullscreenElement)->contentDocument();
+        if (!contentDocument)
             return 0;
-        fullscreenElement = FullscreenElementStack::currentFullScreenElementFrom(document);
+        fullscreenElement = FullscreenElementStack::currentFullScreenElementFrom(*contentDocument);
     }
     if (!fullscreenElement || !fullscreenElement->hasTagName(videoTag))
         return 0;
     RenderObject* renderer = fullscreenElement->renderer();
     if (!renderer)
         return 0;
     return toRenderVideo(renderer);
 }
 
 void RenderLayerCompositor::finishCompositingUpdateForFrameTree(Frame* frame)
@@ skipping 123 matching lines @@
     if (needHierarchyAndGeometryUpdate) {
         // Update the hierarchy of the compositing layers.
         Vector<GraphicsLayer*> childList;
         {
             TRACE_EVENT0("blink_rendering", "RenderLayerCompositor::rebuildCompositingLayerTree");
             rebuildCompositingLayerTree(updateRoot, childList, 0);
         }
 
         // Host the document layer in the RenderView's root layer.
         if (RuntimeEnabledFeatures::overlayFullscreenVideoEnabled() && isMainFrame()) {
-            RenderVideo* video = findFullscreenVideoRenderer(&m_renderView->document());
+            RenderVideo* video = findFullscreenVideoRenderer(m_renderView->document());
             if (video && video->hasCompositedLayerMapping()) {
                 childList.clear();
                 childList.append(video->compositedLayerMapping()->mainGraphicsLayer());
             }
         }
 
         if (childList.isEmpty())
             destroyRootLayer();
         else
             m_rootContentLayer->setChildren(childList);
@@ skipping 2242 matching lines @@
     } else if (graphicsLayer == m_scrollLayer.get()) {
         name = "Frame Scrolling Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebCore