ScriptState used by EventListener::handleEvent() is wrong

Source/bindings/core/v8/ScriptState.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ScriptState_h
 #define ScriptState_h
 
 #include "bindings/core/v8/ScopedPersistent.h"
 #include "bindings/core/v8/V8PerContextData.h"
 #include "wtf/RefCounted.h"
@@ skipping 14 matching lines @@
 class ScriptState : public RefCounted<ScriptState> {
     WTF_MAKE_NONCOPYABLE(ScriptState);
 public:
     class Scope {
     public:
         // You need to make sure that scriptState->context() is not empty before creating a Scope.
         explicit Scope(ScriptState* scriptState)
             : m_handleScope(scriptState->isolate())
             , m_context(scriptState->context())
         {
-            ASSERT(!m_context.IsEmpty());
+            ASSERT(scriptState->contextIsValid());
             m_context->Enter();
         }
 
         ~Scope()
         {
             m_context->Exit();
         }
 
     private:
         v8::HandleScope m_handleScope;
@@ skipping 103 matching lines @@
     }
 
 private:
     RefPtr<ScriptState> m_scriptState;
     ScopedPersistent<v8::Context> m_context;
 };
 
 }
 
 #endif // ScriptState_h