Add ChildMessageFilter, a base class for renderer/worker cross-thread MessageFilter

content/child/service_worker/service_worker_message_filter.cc

Index: content/child/service_worker/service_worker_message_filter.cc
diff --git a/content/child/service_worker/service_worker_message_filter.cc b/content/child/service_worker/service_worker_message_filter.cc
index aaacabec04c89e606dd04d7dc946e6cbee5e9e1f..d3b9aee7e49c0c9295ac832e9a04d520e89a3624 100644
--- a/content/child/service_worker/service_worker_message_filter.cc
+++ b/content/child/service_worker/service_worker_message_filter.cc
@@ -4,43 +4,30 @@
 
 #include "content/child/service_worker/service_worker_message_filter.h"
 
-#include "ipc/ipc_message_macros.h"
-#include "base/bind.h"
-#include "base/message_loop/message_loop_proxy.h"
-#include "base/pickle.h"
 #include "content/child/service_worker/service_worker_dispatcher.h"
 #include "content/child/thread_safe_sender.h"
-#include "webkit/child/worker_task_runner.h"
-
-using webkit_glue::WorkerTaskRunner;
+#include "ipc/ipc_message_macros.h"
 
 namespace content {
 
 ServiceWorkerMessageFilter::ServiceWorkerMessageFilter(ThreadSafeSender* sender)
-    : main_thread_loop_proxy_(base::MessageLoopProxy::current()),
-      thread_safe_sender_(sender) {}
+    : thread_safe_sender_(sender) {}
 
 ServiceWorkerMessageFilter::~ServiceWorkerMessageFilter() {}
 
-bool ServiceWorkerMessageFilter::OnMessageReceived(const IPC::Message& msg) {
+bool ServiceWorkerMessageFilter::OverrideThreadIDForMessage(
+    const IPC::Message& msg, int* ipc_thread_id) {
   if (IPC_MESSAGE_CLASS(msg) != ServiceWorkerMsgStart)
     return false;
-  int thread_id = 0;
-  bool result = PickleIterator(msg).ReadInt(&thread_id);
-  DCHECK(result);
-  base::Closure closure =
-      base::Bind(&ServiceWorkerMessageFilter::DispatchMessage, this, msg);
-  if (!thread_id) {
-    main_thread_loop_proxy_->PostTask(FROM_HERE, closure);
-    return true;
-  }
-  WorkerTaskRunner::Instance()->PostTask(thread_id, closure);
-  return true;
+  return PickleIterator(msg).ReadInt(ipc_thread_id);
 }
 
-void ServiceWorkerMessageFilter::DispatchMessage(const IPC::Message& msg) {
+bool ServiceWorkerMessageFilter::OnMessageReceived(const IPC::Message& msg) {
+  if (IPC_MESSAGE_CLASS(msg) != ServiceWorkerMsgStart)
+    return false;
   ServiceWorkerDispatcher::ThreadSpecificInstance(thread_safe_sender_.get())
       ->OnMessageReceived(msg);
+  return false;
 }
 
 }  // namespace content