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..7f9c720f8d4e11c9360aaa4aa72a5671dcdb8128
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+++ b/content/renderer/gpu/compositor_forwarding_message_filter.h
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+// 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 "base/threading/thread_checker.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 compositor 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 compositor 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 have
+// arrived, all handlers in |multi_handlers_| for routing id will be executed.
+//
+// Note: When we want to add new message, add a new switch case in
+// OnMessageReceived() then add a new Handler for it.
+class CONTENT_EXPORT CompositorForwardingMessageFilter
+    : public IPC::MessageFilter {
+ public:
+  // The handler is invoked on the compositor thread with messages that were
+  // intercepted by this filter.
+  typedef base::Callback<void(const IPC::Message&)> Handler;
+
+  // This filter will intercept messages defined in OnMessageReceived() and run
+  // them by ProcessMessageOnCompositorThread on compositor thread.
+  CompositorForwardingMessageFilter(base::TaskRunner* compositor_task_runner);
+
+  void AddHandlerOnCompositorThread(int routing_id, const Handler& handler);
+  void RemoveHandlerOnCompositorThread(int routing_id, const Handler& handler);
+
+  // MessageFilter methods:
+  virtual bool OnMessageReceived(const IPC::Message& message) override;
+
+ protected:
+  virtual ~CompositorForwardingMessageFilter();
+
+ private:
+  void ProcessMessageOnCompositorThread(const IPC::Message& message);
+
+  // The handler only gets run on the compositor thread.
+  scoped_refptr<base::TaskRunner> compositor_task_runner_;
+
+  // This is used to check some functions that are only running on compositor
+  // thread.
+  base::ThreadChecker compositor_thread_checker_;
+
+  // 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_