Decrease call sites of ScriptState::current()

Source/bindings/v8/custom/V8MutationObserverCustom.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 39 matching lines @@
         return;
     }
 
     v8::Local<v8::Value> arg = info[0];
     if (!arg->IsFunction()) {
         exceptionState.throwTypeError("Callback argument must be a function");
         exceptionState.throwIfNeeded();
         return;
     }
 
-    ExecutionContext* context = currentExecutionContext(info.GetIsolate());
     v8::Handle<v8::Object> wrapper = info.Holder();
 
-    OwnPtr<MutationCallback> callback = V8MutationCallback::create(v8::Handle<v8::Function>::Cast(arg), context, wrapper, info.GetIsolate());
+    OwnPtr<MutationCallback> callback = V8MutationCallback::create(v8::Handle<v8::Function>::Cast(arg), wrapper, ScriptState::current(info.GetIsolate()));
     RefPtrWillBeRawPtr<MutationObserver> observer = MutationObserver::create(callback.release());
 
     V8DOMWrapper::associateObjectWithWrapper<V8MutationObserver>(observer.release(), &wrapperTypeInfo, wrapper, info.GetIsolate(), WrapperConfiguration::Dependent);
     info.GetReturnValue().Set(wrapper);
 }
 
 void V8MutationObserver::visitDOMWrapper(void* object, const v8::Persistent<v8::Object>& wrapper, v8::Isolate* isolate)
 {
     MutationObserver* observer = static_cast<MutationObserver*>(object);
     HashSet<Node*> observedNodes = observer->getObservedNodes();
     for (HashSet<Node*>::iterator it = observedNodes.begin(); it != observedNodes.end(); ++it) {
         v8::UniqueId id(reinterpret_cast<intptr_t>(V8GCController::opaqueRootForGC(*it, isolate)));
         isolate->SetReferenceFromGroup(id, wrapper);
     }
 }
 
 } // namespace WebCore