gpu: Add flag for enabling asynchronous worker context.

gpu/ipc/client/gpu_channel_host.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 "gpu/ipc/client/gpu_channel_host.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/atomic_sequence_num.h"
@@ skipping 320 matching lines @@
 int32_t GpuChannelHost::ReserveImageId() {
   return next_image_id_.GetNext();
 }
 
 int32_t GpuChannelHost::GenerateRouteID() {
   return next_route_id_.GetNext();
 }
 
 int32_t GpuChannelHost::GenerateStreamID() {
   const int32_t stream_id = next_stream_id_.GetNext();
-  DCHECK_NE(0, stream_id);
-  DCHECK_NE(kDefaultStreamId, stream_id);
+  DCHECK_NE(gpu::GPU_STREAM_DEFAULT, stream_id);
   return stream_id;
 }
 
 uint32_t GpuChannelHost::ValidateFlushIDReachedServer(int32_t stream_id,
                                                       bool force_validate) {
   // Store what flush ids we will be validating for all streams.
   base::hash_map<int32_t, uint32_t> validate_flushes;
   uint32_t flushed_stream_flush_id = 0;
   uint32_t verified_stream_flush_id = 0;
   {
@@ skipping 119 matching lines @@
 
   listeners_.clear();
 }
 
 bool GpuChannelHost::MessageFilter::IsLost() const {
   AutoLock lock(lock_);
   return lost_;
 }
 
 }  // namespace gpu