cc: Make separate interface for BeginFrame ipc from OutputSurface

content/renderer/gpu/compositor_external_begin_frame_source.cc

+// 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.
+
+#include "content/renderer/gpu/compositor_external_begin_frame_source.h"
+
+#include "content/common/view_messages.h"
+#include "content/renderer/render_thread_impl.h"
+#include "ipc/ipc_sync_channel.h"
+#include "ipc/ipc_sync_message_filter.h"
+
+namespace content {
+
+CompositorExternalBeginFrameSource::CompositorExternalBeginFrameSource(
+    int routing_id)
+    : begin_frame_source_filter_(
+          RenderThreadImpl::current()->compositor_message_filter()),
+      message_sender_(RenderThreadImpl::current()->sync_message_filter()),
+      routing_id_(routing_id) {
+  DCHECK(begin_frame_source_filter_.get());
+  DCHECK(message_sender_.get());
+  DetachFromThread();
+}
+
+CompositorExternalBeginFrameSource::~CompositorExternalBeginFrameSource() {
+  DCHECK(CalledOnValidThread());
+  if (begin_frame_source_proxy_.get()) {
+    begin_frame_source_proxy_->ClearBeginFrameSource();
+    begin_frame_source_filter_->RemoveHandlerOnCompositorThread(
+                                    routing_id_,
+                                    begin_frame_source_filter_handler_);
+  }
+}
+
+void CompositorExternalBeginFrameSource::OnNeedsBeginFramesChange(
+    bool needs_begin_frames) {
+  DCHECK(CalledOnValidThread());
+  Send(new ViewHostMsg_SetNeedsBeginFrames(routing_id_, needs_begin_frames));
+}
+
+void CompositorExternalBeginFrameSource::SetClientReady() {
+  DCHECK(CalledOnValidThread());
+  DCHECK(!begin_frame_source_proxy_.get());
+  begin_frame_source_proxy_ =
+      new CompositorExternalBeginFrameSourceProxy(this);
+  begin_frame_source_filter_handler_ =
+       base::Bind(&CompositorExternalBeginFrameSourceProxy::OnMessageReceived,
+                 begin_frame_source_proxy_);

[dcheng, 2014/11/10 22:56:15]

Indents on this and the next 4 lines looks funny. Is this from git cl format--if
so, I need to file a bug against clang-format =)

(Note that clang-format currently mangles message map macros so I wouldn't
advocate running across the entire patch anyway, unless you take care to fix the
message maps manually =/)

[simonhong, 2014/11/11 12:54:15]

changed to less funny :)
git cl format didn't complain about this.

+  begin_frame_source_filter_->AddHandlerOnCompositorThread(
+                                  routing_id_,
+                                  begin_frame_source_filter_handler_);
+}
+
+void CompositorExternalBeginFrameSource::OnMessageReceived(
+    const IPC::Message& message) {
+  DCHECK(CalledOnValidThread());
+  DCHECK(begin_frame_source_proxy_.get());
+  IPC_BEGIN_MESSAGE_MAP(CompositorExternalBeginFrameSource, message)
+    IPC_MESSAGE_HANDLER(ViewMsg_BeginFrame, OnBeginFrame);

[dcheng, 2014/11/10 22:56:15]

I don't think a ; is needed, and most people usually leave it out. We should do
the same here for consistency. IPC message map macros are weird =/

[simonhong, 2014/11/11 12:54:15]

Done.

+  IPC_END_MESSAGE_MAP();
+}
+
+void CompositorExternalBeginFrameSource::OnBeginFrame(
+  const cc::BeginFrameArgs& args) {
+  DCHECK(CalledOnValidThread());
+  CallOnBeginFrame(args);
+}
+
+bool CompositorExternalBeginFrameSource::Send(IPC::Message* message) {
+  return message_sender_->Send(message);
+}
+
+}  // namespace content