cc: Make separate interface for BeginFrame ipc from OutputSurface

content/renderer/gpu/compositor_forwarding_message_filter.h

Index: content/renderer/gpu/compositor_forwarding_message_filter.h
diff --git a/content/renderer/gpu/compositor_forwarding_message_filter.h b/content/renderer/gpu/compositor_forwarding_message_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..011ae4fe7c6b81948ac63d748dfa343f3e8b12c4
--- /dev/null
+++ b/content/renderer/gpu/compositor_forwarding_message_filter.h
@@ -0,0 +1,77 @@
+// Copyright 2014 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.
+
+#ifndef CONTENT_RENDERER_GPU_COMPOSITOR_FORWARDING_MESSAGE_FILTER_H_
+#define CONTENT_RENDERER_GPU_COMPOSITOR_FORWARDING_MESSAGE_FILTER_H_
+
+#include <map>
+#include <set>
+
+#include "base/bind.h"
+#include "base/callback_forward.h"
+#include "base/synchronization/lock.h"
+#include "base/task_runner.h"
+#include "content/common/content_export.h"
+#include "ipc/message_filter.h"
+
+namespace content {
+
+// This class can be used to intercept routed messages and
+// deliver them to a different task runner than they would otherwise
+// be sent. Messages are filtered based on type. To route these messages,
+// add a Handler to the filter.
+//
+// The user of this class implements CompositorForwardingMessageFilter::Handler,
+// which will receive the intercepted messages, on the specified target thread.
+// The caller must ensure that each handler in |multi_handlers_| outlives the
+// lifetime of the filter.
+// User can add multiple handlers for specific routing id. When messages are
+// arrived, all handlers in |multi_handlers_| for routing id will be executed.

[brianderson, 2014/10/24 20:46:58]

are arrived -> have arrived

[simonhong, 2014/10/29 14:47:14]

Done.

+class CONTENT_EXPORT CompositorForwardingMessageFilter
+    : public IPC::MessageFilter {
+ public:
+  static CompositorForwardingMessageFilter* Create(
+      base::TaskRunner* target_task_runner);
+  // The handler is invoked on the thread associated with
+  // |target_task_runner_| with messages that were intercepted by this filter.
+  typedef base::Callback<void(const IPC::Message&)> Handler;
+
+  // Define the message handler to be filtered.
+  void AddRoute(int routing_id, const Handler& handler);
+  void RemoveRoute(int routing_id, const Handler& handler);
+
+  // MessageFilter methods:
+  virtual bool OnMessageReceived(const IPC::Message& message) override;
+
+ protected:
+  // This filter will intercept |message_ids_to_filter| and post
+  // them to the provided |target_task_runner|, where they will be given
+  // to all handlers in the |multi_handlers_|.
+  CompositorForwardingMessageFilter(
+      const uint32* message_ids_to_filter,
+      size_t num_message_ids_to_filter,
+      base::TaskRunner* target_task_runner);
+
+  virtual ~CompositorForwardingMessageFilter();
+
+ private:
+  std::set<int> message_ids_to_filter_;
+
+  // The handler only gets run on the thread corresponding to
+  // target_task_runner_.
+  scoped_refptr<base::TaskRunner> target_task_runner_;
+
+  // Protects access to |multi_handlers_|.
+  base::Lock handlers_lock_;
+
+  // Maps the routing_id for which messages should be filtered and handlers
+  // which will be routed.
+  std::multimap<int, Handler> multi_handlers_;
+
+  DISALLOW_COPY_AND_ASSIGN(CompositorForwardingMessageFilter);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_GPU_COMPOSITOR_FORWARDING_MESSAGE_FILTER_H_