Implemented new fence syncs which replaces the old sync points.

content/common/gpu/gpu_channel.cc

 // Copyright (c) 2012 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/common/gpu/gpu_channel.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
 
@@ skipping 788 matching lines @@
   gpu_channel_manager_->RemoveChannel(client_id_);
 }
 
 bool GpuChannel::OnControlMessageReceived(const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(GpuChannel, msg)
     IPC_MESSAGE_HANDLER(GpuChannelMsg_CreateOffscreenCommandBuffer,
                         OnCreateOffscreenCommandBuffer)
     IPC_MESSAGE_HANDLER(GpuChannelMsg_DestroyCommandBuffer,
                         OnDestroyCommandBuffer)
+    IPC_MESSAGE_HANDLER(GpuChannelMsg_Nop,
+                        OnNop)

[piman, 2015/09/26 00:09:51]

You want to handle this on the IO thread (in the filter).
Once this arrives on the IO thread, you know all previous messages have arrived
too, hence you generated a valid ordering id for them, they're in the queue,
etc. and that's the important part.

You don't want to handle it on the main thread, because it may be busy executing
blocking commands (e.g. glFinish etc).

[David Yen, 2015/09/28 17:38:18]

Done.

     IPC_MESSAGE_HANDLER_DELAY_REPLY(GpuMsg_CreateJpegDecoder,
                                     OnCreateJpegDecoder)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   DCHECK(handled) << msg.type();
   return handled;
 }
 
 scoped_refptr<gpu::SyncPointClientState> GpuChannel::GetSyncPointClientState() {
   return message_queue_->GetSyncPointClientState();
@@ skipping 195 matching lines @@
   }
 }
 
 void GpuChannel::OnCreateJpegDecoder(int32 route_id, IPC::Message* reply_msg) {
   if (!jpeg_decoder_) {
     jpeg_decoder_.reset(new GpuJpegDecodeAccelerator(this, io_task_runner_));
   }
   jpeg_decoder_->AddClient(route_id, reply_msg);
 }
 
+void GpuChannel::OnNop() {}
+
 void GpuChannel::CacheShader(const std::string& key,
                              const std::string& shader) {
   gpu_channel_manager_->Send(
       new GpuHostMsg_CacheShader(client_id_, key, shader));
 }
 
 void GpuChannel::AddFilter(IPC::MessageFilter* filter) {
   io_task_runner_->PostTask(
       FROM_HERE, base::Bind(&GpuChannelMessageFilter::AddChannelFilter,
                             filter_, make_scoped_refptr(filter)));
@@ skipping 50 matching lines @@
     }
   }
 }
 
 void GpuChannel::HandleUpdateValueState(
     unsigned int target, const gpu::ValueState& state) {
   pending_valuebuffer_state_->UpdateState(target, state);
 }
 
 }  // namespace content