Merge 78921

Source/WebCore/html/canvas/WebKitLoseContext.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 37 matching lines @@
     return WebKitLoseContextName;
 }
 
 PassRefPtr<WebKitLoseContext> WebKitLoseContext::create(WebGLRenderingContext* context)
 {
     return adoptRef(new WebKitLoseContext(context));
 }
 
 void WebKitLoseContext::loseContext()
 {
-    m_context->forceLostContext();
+    if (m_context)
+        m_context->forceLostContext();
 }
 
 } // namespace WebCore
 
 #endif // ENABLE(3D_CANVAS)