Wrap GCed raw pointer parameters of WTF::bind with Persistent

third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp

 /*
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. 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.
@@ skipping 643 matching lines @@
 
 void HTMLCanvasElement::toBlob(BlobCallback* callback, const String& mimeType, const ScriptValue& qualityArgument, ExceptionState& exceptionState)
 {
     if (!originClean()) {
         exceptionState.throwSecurityError("Tainted canvases may not be exported.");
         return;
     }
 
     if (!isPaintable()) {
         // If the canvas element's bitmap has no pixels
-        Platform::current()->mainThread()->getWebTaskRunner()->postTask(BLINK_FROM_HERE, bind(&BlobCallback::handleEvent, callback, nullptr));
+        Platform::current()->mainThread()->getWebTaskRunner()->postTask(BLINK_FROM_HERE, bind(&BlobCallback::handleEvent, wrapCrossThreadPersistent(callback), nullptr));
         return;
     }
 
     double quality = UndefinedQualityValue;
     if (!qualityArgument.isEmpty()) {
         v8::Local<v8::Value> v8Value = qualityArgument.v8Value();
         if (v8Value->IsNumber()) {
             quality = v8Value.As<v8::Number>()->Value();
         }
     }
@@ skipping 490 matching lines @@
         return m_context->getIdFromControl(element);
     return String();
 }
 
 void HTMLCanvasElement::createSurfaceLayerBridge()
 {
     m_surfaceLayerBridge = adoptPtr(new CanvasSurfaceLayerBridge());
 }
 
 } // namespace blink