Add an API to report debugName in GraphicsLayer

Source/core/platform/graphics/GraphicsLayer.h

Index: Source/core/platform/graphics/GraphicsLayer.h
diff --git a/Source/core/platform/graphics/GraphicsLayer.h b/Source/core/platform/graphics/GraphicsLayer.h
index 72206c30f2d891931431cb3a92570a1b100f3cc1..9b1f55d60b4ca1b95f0345e19364abb0a123b808 100644
--- a/Source/core/platform/graphics/GraphicsLayer.h
+++ b/Source/core/platform/graphics/GraphicsLayer.h
@@ -203,7 +203,7 @@ protected:
 // GraphicsLayer is an abstraction for a rendering surface with backing store,
 // which may have associated transformation and animations.
 
-class GraphicsLayer : public GraphicsContextPainter, public WebKit::WebAnimationDelegate, public WebKit::WebLayerScrollClient {
+class GraphicsLayer : public GraphicsContextPainter, public WebKit::WebAnimationDelegate, public WebKit::WebLayerScrollClient, public WebKit::WebLayerClient {
     WTF_MAKE_NONCOPYABLE(GraphicsLayer); WTF_MAKE_FAST_ALLOCATED;
 public:
     enum ContentsLayerPurpose {
@@ -219,9 +219,7 @@ public:
 
     GraphicsLayerClient* client() const { return m_client; }
 
-    // Layer name. Only used to identify layers in debug output
-    const String& name() const { return m_name; }
-    void setName(const String&);
+    virtual WebKit::WebString debugName(WebKit::WebLayer*) OVERRIDE;

[jamesr, 2013/07/30 17:37:40]

document where this override is coming from with a comment like "//
WebKit::WebLayerClient implementation."

[qiankun, 2013/07/31 11:16:28]

Done.

 
     // Layer ID from platform-specific layer. Only used to identify layers in the compositor for debugging purposes.
     int debugID() const;
@@ -486,7 +484,6 @@ protected:
     void getDebugBorderInfo(Color&, float& width) const;
 
     // Helper functions used by settors to keep layer's the state consistent.
-    void updateNames();
     void updateChildList();
     void updateLayerIsDrawable();
     void updateContentsRect();
@@ -497,7 +494,6 @@ protected:
     WebKit::WebLayer* contentsLayerIfRegistered();
 
     GraphicsLayerClient* m_client;
-    String m_name;
     
     // Offset from the owning renderer
     IntSize m_offsetFromRenderer;
@@ -543,8 +539,6 @@ protected:
 
     int m_repaintCount;
 
-    String m_nameBase;
-
     Color m_contentsSolidColor;
 
     OwnPtr<WebKit::WebContentLayer> m_layer;