Make WebGL extensions get lost when context is lost.

Source/core/html/canvas/WebGLLoseContext.cpp

 /*
  * Copyright (C) 2010 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 23 matching lines @@
 WebGLLoseContext::WebGLLoseContext(WebGLRenderingContext* context)
     : WebGLExtension(context)
 {
     ScriptWrappable::init(this);
 }
 
 WebGLLoseContext::~WebGLLoseContext()
 {
 }
 
+void WebGLLoseContext::lose(bool force)
+{
+    if (force)
+        WebGLExtension::lose(true);
+}
+
 WebGLExtension::ExtensionName WebGLLoseContext::getName() const
 {
     return WebGLLoseContextName;
 }
 
-PassOwnPtr<WebGLLoseContext> WebGLLoseContext::create(WebGLRenderingContext* context)
+PassRefPtr<WebGLLoseContext> WebGLLoseContext::create(WebGLRenderingContext* context)
 {
-    return adoptPtr(new WebGLLoseContext(context));
+    return adoptRef(new WebGLLoseContext(context));
 }
 
 void WebGLLoseContext::loseContext()
 {
-    m_context->forceLostContext(WebGLRenderingContext::SyntheticLostContext);
+    if (!isLost())
+        m_context->forceLostContext(WebGLRenderingContext::SyntheticLostContext);
 }
 
 void WebGLLoseContext::restoreContext()
 {
-    m_context->forceRestoreContext();
+    if (!isLost())
+        m_context->forceRestoreContext();
 }
 
 bool WebGLLoseContext::supported(WebGLRenderingContext*)
 {
     return true;
 }
 
 const char* WebGLLoseContext::getExtensionName()
 {
     return "WEBGL_lose_context";
 }
 
 } // namespace WebCore