DevTools: add instrumentation for deferred canvas rasterization

Source/core/platform/PlatformInstrumentation.cpp

 /*
  * Copyright (C) 2012 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 20 matching lines @@
 #include "config.h"
 
 #include "core/platform/PlatformInstrumentation.h"
 
 namespace WebCore {
 
 const char PlatformInstrumentation::CategoryName[] = "webkit";
 
 const char PlatformInstrumentation::ImageDecodeEvent[] = "Decode Image";
 const char PlatformInstrumentation::ImageResizeEvent[] = "Resize Image";
+const char PlatformInstrumentation::RasterizeCanvasEvent[] = "Rasterize Canvas";
 
 const char PlatformInstrumentation::ImageTypeArgument[] = "imageType";
 const char PlatformInstrumentation::CachedArgument[] = "cached";
 
 PlatformInstrumentationClient* PlatformInstrumentation::m_client;
 
 PlatformInstrumentationClient::~PlatformInstrumentationClient()
 {
 }
 
 void PlatformInstrumentation::setClient(PlatformInstrumentationClient* client)
 {
     m_client = client;
 }
 
 }