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

content/child/cross_thread_message_filter.cc

Index: content/child/cross_thread_message_filter.cc
diff --git a/content/child/cross_thread_message_filter.cc b/content/child/cross_thread_message_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..14db21bf56dcc89b361b2dd28d7c2fc2a272cb4b
--- /dev/null
+++ b/content/child/cross_thread_message_filter.cc
@@ -0,0 +1,59 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/child/cross_thread_message_filter.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/location.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "webkit/child/worker_task_runner.h"
+
+namespace content {
+
+class CrossThreadMessageFilter::Internal
+    : public IPC::ChannelProxy::MessageFilter {
+ public:
+  explicit Internal(CrossThreadMessageFilter* filter)
+      : filter_(filter),
+        main_thread_loop_proxy_(base::MessageLoopProxy::current()) {}
+
+  virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE {
+    int ipc_thread_id = 0;
+    if (!filter_->OverrideThreadIDForMessage(msg, &ipc_thread_id))
+      return filter_->OnMessageReceived(msg);
+
+    base::Closure closure = base::Bind(
+        base::IgnoreResult(&CrossThreadMessageFilter::OnMessageReceived),
+        filter_, msg);
+    if (!ipc_thread_id) {

[jam, 2013/11/08 19:51:59]

we should keep the ipc_thread_id stuff in child classes. this class should be
generic so that it could be used with more than just blink's worker threads.  so
like BrowserMessageFilter, OverrideTaskRunnerForMessage would return a
base::TaskRunner

[michaeln, 2013/11/09 01:52:10]

+1 using the base::TaskRunner abstraction for this, we just need an impl that
uses WorkerTaskRunner::Instance()->PostTask() under the covers.

[kinuko, 2013/11/15 14:40:36]

Done.  (If I should separate a CL for adding TaskRunner for webkit worker
threads I can do so too)

+      main_thread_loop_proxy_->PostTask(FROM_HERE, closure);
+      return true;
+    }
+    if (!webkit_glue::WorkerTaskRunner::Instance()->PostTask(
+            ipc_thread_id, closure))
+      filter_->OnStaleMessageReceived(msg);
+    return true;
+  }
+
+ private:
+  virtual ~Internal() {}
+  scoped_refptr<CrossThreadMessageFilter> filter_;
+  scoped_refptr<base::MessageLoopProxy> main_thread_loop_proxy_;
+
+  DISALLOW_COPY_AND_ASSIGN(Internal);
+};
+
+CrossThreadMessageFilter::CrossThreadMessageFilter()
+    : internal_(NULL) {}
+
+CrossThreadMessageFilter::~CrossThreadMessageFilter() {}
+
+IPC::ChannelProxy::MessageFilter* CrossThreadMessageFilter::GetFilter() {
+  if (!internal_)
+    internal_ = new Internal(this);
+  return internal_;
+}
+
+}  // namespace content