ServiceWorker: Introduce ExtendableMessageEvent to replace MessageEvent

content/child/service_worker/web_service_worker_impl.cc

Index: content/child/service_worker/web_service_worker_impl.cc
diff --git a/content/child/service_worker/web_service_worker_impl.cc b/content/child/service_worker/web_service_worker_impl.cc
index 0939aaa7b6d83c6056b8f34151179307418ace4c..ba47b1a15fe5a211e58308ba443532df7c3e7ed0 100644
--- a/content/child/service_worker/web_service_worker_impl.cc
+++ b/content/child/service_worker/web_service_worker_impl.cc
@@ -21,9 +21,11 @@ namespace content {
 
 WebServiceWorkerImpl::WebServiceWorkerImpl(
     scoped_ptr<ServiceWorkerHandleReference> handle_ref,
+    int provider_id,
     ThreadSafeSender* thread_safe_sender)
     : handle_ref_(handle_ref.Pass()),
       state_(handle_ref_->state()),
+      provider_id_(provider_id),
       thread_safe_sender_(thread_safe_sender),
       proxy_(NULL) {
   ServiceWorkerDispatcher* dispatcher =
@@ -66,8 +68,7 @@ blink::WebServiceWorkerState WebServiceWorkerImpl::state() const {
 void WebServiceWorkerImpl::postMessage(const WebString& message,
                                        WebMessagePortChannelArray* channels) {
   thread_safe_sender_->Send(new ServiceWorkerHostMsg_PostMessageToWorker(
-      handle_ref_->handle_id(),
-      message,
+      handle_ref_->handle_id(), provider_id_, message,
       WebMessagePortChannelImpl::ExtractMessagePortIDs(channels)));
 }