[ServiceWorker, PushMessaging] Use ScriptPromiseResolverWithContext.

Source/bindings/v8/ScriptPromiseResolverWithContext.h

Index: Source/bindings/v8/ScriptPromiseResolverWithContext.h
diff --git a/Source/bindings/v8/ScriptPromiseResolverWithContext.h b/Source/bindings/v8/ScriptPromiseResolverWithContext.h
index f373fa9f3e1347a6ea148a86c18c3db1f09632ff..92ab7a6b8b0dcd506e8cf1fa98f5d410c44d5471 100644
--- a/Source/bindings/v8/ScriptPromiseResolverWithContext.h
+++ b/Source/bindings/v8/ScriptPromiseResolverWithContext.h
@@ -62,6 +62,8 @@ public:
             resolveOrRejectImmediately(&m_timer);
     }
 
+    NewScriptState* scriptState() { return m_scriptState.get(); }
+
     // Note that an empty ScriptPromise will be returned after resolve or
     // reject is called.
     ScriptPromise promise()
@@ -108,7 +110,7 @@ private:
     void clear();
 
     ResolutionState m_state;
-    RefPtr<NewScriptState> m_scriptState;
+    const RefPtr<NewScriptState> m_scriptState;
     Timer<ScriptPromiseResolverWithContext> m_timer;
     RefPtr<ScriptPromiseResolver> m_resolver;
     ScopedPersistent<v8::Value> m_value;