Have Frame::script() return a reference

Source/bindings/v8/ScriptState.cpp

 /*
  * Copyright (C) 2009, 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 92 matching lines @@
 
 void ScriptState::setEvalEnabled(bool enabled)
 {
     v8::HandleScope handleScope(m_isolate);
     return context()->AllowCodeGenerationFromStrings(enabled);
 }
 
 ScriptState* mainWorldScriptState(Frame* frame)
 {
     v8::HandleScope handleScope(toIsolate(frame));
-    return ScriptState::forContext(frame->script()->mainWorldContext());
+    return ScriptState::forContext(frame->script().mainWorldContext());
 }
 
 ScriptState* scriptStateFromWorkerGlobalScope(WorkerGlobalScope* workerGlobalScope)
 {
     WorkerScriptController* script = workerGlobalScope->script();
     if (!script)
         return 0;
 
     v8::HandleScope handleScope(script->isolate());
     return ScriptState::forContext(script->context());
 }
 
 }