Ignore V8's message handler that is invoked while we're initializing a window

Source/bindings/v8/V8Initializer.cpp

 /*
  * Copyright (C) 2009 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 67 matching lines @@
 
 static void reportFatalErrorInMainThread(const char* location, const char* message)
 {
     int memoryUsageMB = blink::Platform::current()->actualMemoryUsageMB();
     printf("V8 error: %s (%s).  Current memory usage: %d MB\n", message, location, memoryUsageMB);
     CRASH();
 }
 
 static void messageHandlerInMainThread(v8::Handle<v8::Message> message, v8::Handle<v8::Value> data)
 {
+    ASSERT(isMainThread());
+    // It's possible that messageHandlerInMainThread() is invoked while we're initializing a window.
+    // In that half-baked situation, we don't have a valid context nor a valid world,
+    // so just return immediately.
+    if (DOMWrapperWorld::windowIsBeingInitialized())
+        return;
+
     v8::Isolate* isolate = v8::Isolate::GetCurrent();
     // If called during context initialization, there will be no entered window.
     DOMWindow* enteredWindow = enteredDOMWindow(isolate);
     if (!enteredWindow || !enteredWindow->isCurrentlyDisplayedInFrame())
         return;
 
     String errorMessage = toCoreString(message->Get());
 
     v8::Handle<v8::StackTrace> stackTrace = message->GetStackTrace();
     RefPtr<ScriptCallStack> callStack;
@@ skipping 133 matching lines @@
     v8::V8::AddMessageListener(messageHandlerInWorker);
     v8::V8::SetFatalErrorHandler(reportFatalErrorInWorker);
 
     v8::ResourceConstraints resourceConstraints;
     uint32_t here;
     resourceConstraints.set_stack_limit(&here - kWorkerMaxStackSize / sizeof(uint32_t*));
     v8::SetResourceConstraints(isolate, &resourceConstraints);
 }
 
 } // namespace WebCore