Add RELEASE_ASSERT for ensuring that we have no empty context to V8WrapperInstantiationScope.

Source/bindings/v8/V8DOMWrapper.h

 /*
  * 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 132 matching lines @@
     }
 
     class V8WrapperInstantiationScope {
     public:
         V8WrapperInstantiationScope(v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
             : m_didEnterContext(false)
             , m_context(isolate->GetCurrentContext())
         {
             // FIXME: Remove all empty creationContexts from caller sites.
             // If a creationContext is empty, we will end up creating a new object
             // in the context currently entered. This is wrong.

[haraken, 2014/06/09 06:47:03]

Would you update this FIXME to clarify why we have a RELEASE_ASSERT here?

[tasak, 2014/06/12 02:08:07]

Done.

-            if (creationContext.IsEmpty())
-                return;
+            RELEASE_ASSERT(!creationContext.IsEmpty());
             v8::Handle<v8::Context> contextForWrapper = creationContext->CreationContext();
             // For performance, we enter the context only if the currently running context
             // is different from the context that we are about to enter.
             if (contextForWrapper == m_context)
                 return;
             m_context = v8::Local<v8::Context>::New(isolate, contextForWrapper);
             m_didEnterContext = true;
             m_context->Enter();
         }
 
         ~V8WrapperInstantiationScope()
         {
             if (!m_didEnterContext)
                 return;
             m_context->Exit();
         }
 
         v8::Handle<v8::Context> context() const { return m_context; }
 
     private:
         bool m_didEnterContext;
         v8::Handle<v8::Context> m_context;
     };
 
 }
 
 #endif // V8DOMWrapper_h