DevTools: expose layer compositing reasons and paint count via layer tree agent

Source/core/inspector/InspectorLayerTreeAgent.h

 /*
  * Copyright (C) 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Google 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.
@@ skipping 26 matching lines @@
 #include "core/rendering/RenderLayer.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 class InspectorDOMAgent;
 class InstrumentingAgents;
 class Page;
+class RenderLayerCompositor;
 
 typedef String ErrorString;
 
 class InspectorLayerTreeAgent : public InspectorBaseAgent<InspectorLayerTreeAgent>, public InspectorBackendDispatcher::LayerTreeCommandHandler {
 public:
     static PassOwnPtr<InspectorLayerTreeAgent> create(InstrumentingAgents* instrumentingAgents, InspectorCompositeState* state, InspectorDOMAgent* domAgent, Page* page)
     {
         return adoptPtr(new InspectorLayerTreeAgent(instrumentingAgents, state, domAgent, page));
     }
     ~InspectorLayerTreeAgent();
 
     virtual void setFrontend(InspectorFrontend*);
     virtual void clearFrontend();
     virtual void restore();
 
     void didCommitLoad(Frame*, DocumentLoader*);
     void layerTreeDidChange();
 
     // Called from the front-end.
     virtual void enable(ErrorString*);
     virtual void disable(ErrorString*);
     virtual void getLayers(ErrorString*, const int* nodeId, RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::Layer> >&);
+    virtual void reasonsForCompositingLayer(ErrorString*, const String& layerId, RefPtr<TypeBuilder::LayerTree::CompositingReasons>&);
 
 private:
     InspectorLayerTreeAgent(InstrumentingAgents*, InspectorCompositeState*, InspectorDOMAgent*, Page*);
 
+    RenderLayerCompositor* renderLayerCompositor(ErrorString*);
+    GraphicsLayer* layerById(ErrorString*, const String& layerId);
+    int idForNode(ErrorString*, Node*);
+
     void gatherLayersUsingRenderObjectHierarchy(ErrorString*, RenderObject*, RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::Layer> >&);
     void gatherLayersUsingRenderLayerHierarchy(ErrorString*, RenderLayer*, RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::Layer> >&);
     void gatherLayersUsingGraphicsLayerHierarchy(ErrorString*, GraphicsLayer*, RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::Layer> >&);
     void addRenderLayerBacking(ErrorString*, RenderLayerBacking*, Node*, RefPtr<TypeBuilder::Array<TypeBuilder::LayerTree::Layer> >&);
 
-    int idForNode(ErrorString*, Node*);
-
     InspectorFrontend::LayerTree* m_frontend;
     Page* m_page;
     InspectorDOMAgent* m_domAgent;
 
     HashMap<const RenderLayer*, String> m_documentLayerToIdMap;
 };
 
 } // namespace WebCore
 
 
 #endif // !defined(InspectorLayerTreeAgent_h)