Use UI message loop for in process GPU thread on Windows

content/browser/gpu/gpu_process_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 "content/browser/gpu/gpu_process_host.h"
 
 #include "base/base64.h"
 #include "base/base_switches.h"
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 494 matching lines @@
   if (in_process_) {
     DCHECK(g_gpu_main_thread_factory);
     base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
     command_line->AppendSwitch(switches::kDisableGpuWatchdog);
 
     GpuDataManagerImpl* gpu_data_manager = GpuDataManagerImpl::GetInstance();
     DCHECK(gpu_data_manager);
     gpu_data_manager->AppendGpuCommandLine(command_line);
 
     in_process_gpu_thread_.reset(g_gpu_main_thread_factory(channel_id));
-    in_process_gpu_thread_->Start();
+    base::Thread::Options options;
+#if defined(OS_WIN)
+    // WGL needs to create its own window and pump messages on it.
+    options.message_loop_type = base::MessageLoop::TYPE_UI;

[Ken Russell (switch to Gerrit), 2014/10/11 03:04:32]

Is there any benefit to checking if --use-gl=desktop was passed, and only
setting this option if so?

+#endif
+    in_process_gpu_thread_->StartWithOptions(options);
 
     OnProcessLaunched();  // Fake a callback that the process is ready.
   } else if (!LaunchGpuProcess(channel_id)) {
     return false;
   }
 
   if (!Send(new GpuMsg_Initialize()))
     return false;
 
   return true;
@@ skipping 532 matching lines @@
   TRACE_EVENT0("gpu", "GpuProcessHost::OnCacheShader");
   ClientIdToShaderCacheMap::iterator iter =
       client_id_to_shader_cache_.find(client_id);
   // If the cache doesn't exist then this is an off the record profile.
   if (iter == client_id_to_shader_cache_.end())
     return;
   iter->second->Cache(GetShaderPrefixKey() + ":" + key, shader);
 }
 
 }  // namespace content