bindings: Stop using the given creationContext in public APIs.

Source/web/WebBlob.cpp

 /*
  * Copyright (C) 2011 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 61 matching lines @@
     m_private = other.m_private;
 }
 
 WebString WebBlob::uuid()
 {
     if (!m_private.get())
         return WebString();
     return m_private->uuid();
 }
 
-v8::Local<v8::Value> WebBlob::toV8Value(v8::Local<v8::Object> creationContext, v8::Isolate* isolate)
+v8::Local<v8::Value> WebBlob::toV8Value(v8::Local<v8::Object> /* creationContext */, v8::Isolate* isolate)
 {
+    // We no longer use |creationContext| because it's often misused and points
+    // to a context faked by user script.
     if (!m_private.get())
         return v8::Local<v8::Value>();
-    return toV8(m_private.get(), creationContext, isolate);
+    return toV8(m_private.get(), isolate->GetCurrentContext()->Global(), isolate);
 }
 
 WebBlob::WebBlob(Blob* blob)
     : m_private(blob)
 {
 }
 
 WebBlob& WebBlob::operator=(Blob* blob)
 {
     m_private = blob;
     return *this;
 }
 
 } // namespace blink