Make WebGL extensions get lost when context is lost.

Source/core/html/canvas/WebGLDebugRendererInfo.cpp

 /*
  * Copyright (C) 2011 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.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 15 matching lines @@
 #include "config.h"
 
 #include "core/html/canvas/WebGLDebugRendererInfo.h"
 
 namespace WebCore {
 
 WebGLDebugRendererInfo::WebGLDebugRendererInfo(WebGLRenderingContext* context)
     : WebGLExtension(context)
 {
     ScriptWrappable::init(this);
+    enable();
 }
 
 WebGLDebugRendererInfo::~WebGLDebugRendererInfo()
 {
 }
 
+void WebGLDebugRendererInfo::enable()
+{
+}
+
 WebGLExtension::ExtensionName WebGLDebugRendererInfo::getName() const
 {
     return WebGLDebugRendererInfoName;
 }
 
 PassOwnPtr<WebGLDebugRendererInfo> WebGLDebugRendererInfo::create(WebGLRenderingContext* context)
 {
     return adoptPtr(new WebGLDebugRendererInfo(context));
 }
 
 bool WebGLDebugRendererInfo::supported(WebGLRenderingContext*)
 {
     return true;
 }
 
 const char* WebGLDebugRendererInfo::getExtensionName()
 {
     return "WEBGL_debug_renderer_info";
 }
 
 } // namespace WebCore