Decrease call sites of ScriptState::current()

Source/bindings/v8/V8MutationCallback.h

Index: Source/bindings/v8/V8MutationCallback.h
diff --git a/Source/bindings/v8/V8MutationCallback.h b/Source/bindings/v8/V8MutationCallback.h
index 4a2478f8106ca9c194a14550fcb53cdeea5b7a1b..fc5589a629b714e556fcb853ad8b5d932ad87304 100644
--- a/Source/bindings/v8/V8MutationCallback.h
+++ b/Source/bindings/v8/V8MutationCallback.h
@@ -40,17 +40,16 @@ class ExecutionContext;
 
 class V8MutationCallback FINAL : public MutationCallback, public ActiveDOMCallback {
 public:
-    static PassOwnPtr<V8MutationCallback> create(v8::Handle<v8::Function> callback, ExecutionContext* context, v8::Handle<v8::Object> owner, v8::Isolate* isolate)
+    static PassOwnPtr<V8MutationCallback> create(v8::Handle<v8::Function> callback, v8::Handle<v8::Object> owner, ScriptState* scriptState)
     {
-        ASSERT(context);
-        return adoptPtr(new V8MutationCallback(callback, context, owner, isolate));
+        return adoptPtr(new V8MutationCallback(callback, owner, scriptState));
     }
 
     virtual void call(const WillBeHeapVector<RefPtrWillBeMember<MutationRecord> >&, MutationObserver*) OVERRIDE;
     virtual ExecutionContext* executionContext() const OVERRIDE { return ContextLifecycleObserver::executionContext(); }
 
 private:
-    V8MutationCallback(v8::Handle<v8::Function>, ExecutionContext*, v8::Handle<v8::Object>, v8::Isolate*);
+    V8MutationCallback(v8::Handle<v8::Function>, v8::Handle<v8::Object>, ScriptState*);
 
     static void setWeakCallback(const v8::WeakCallbackData<v8::Function, V8MutationCallback>&);