Deduplicating compositing scrollingCoordinator helper

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 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 144 matching lines @@
 static inline bool isAcceleratedContents(LayoutObject& layoutObject) {
   return isAcceleratedCanvas(layoutObject) ||
          (layoutObject.isEmbeddedObject() &&
           toLayoutEmbeddedObject(layoutObject)
               .requiresAcceleratedCompositing()) ||
          layoutObject.isVideo();
 }
 
 // Get the scrolling coordinator in a way that works inside
 // CompositedLayerMapping's destructor.
-static ScrollingCoordinator* scrollingCoordinatorFromLayer(PaintLayer& layer) {

[Xianzhu, 2017/04/07 19:26:19]

It seems better to be PaintLayer::getScrollingCoordinator().

Then we can also use it at
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/paint/Pai....

[Daniel Bratell, 2017/04/08 08:08:24]

Done.

Note that the null checks were not identical at the different places so it did
not replace all the code in the PaintLayer destructor. But then, the destructor
is a special place.

+ScrollingCoordinator* CompositedLayerMapping::scrollingCoordinatorFromLayer(
+    PaintLayer& layer) {
   Page* page = layer.layoutObject().frame()->page();
   return (!page) ? nullptr : page->scrollingCoordinator();
 }
 
 CompositedLayerMapping::CompositedLayerMapping(PaintLayer& layer)
     : m_owningLayer(layer),
       m_contentOffsetInCompositingLayerDirty(false),
       m_pendingUpdateScope(GraphicsLayerUpdateNone),
       m_isMainFrameLayoutViewLayer(false),
       m_backgroundLayerPaintsFixedRootBackground(false),
@@ skipping 3370 matching lines @@
   } else if (graphicsLayer == m_decorationOutlineLayer.get()) {
     name = "Decoration Layer";
   } else {
     NOTREACHED();
   }
 
   return name;
 }
 
 }  // namespace blink