Re-land: cc: Use worker context for one-copy tile initialization.

content/common/gpu/client/command_buffer_metrics.h

 // Copyright 2015 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_COMMON_GPU_CLIENT_COMMAND_BUFFER_METRICS_H_
 #define CONTENT_COMMON_GPU_CLIENT_COMMAND_BUFFER_METRICS_H_
 
 #include <string>
 
 #include "gpu/command_buffer/common/constants.h"
 
 namespace content {
 
 enum CommandBufferContextType {
   BROWSER_COMPOSITOR_ONSCREEN_CONTEXT,
   BROWSER_OFFSCREEN_MAINTHREAD_CONTEXT,
+  BROWSER_WORKER_CONTEXT,
   RENDER_COMPOSITOR_CONTEXT,
   RENDER_WORKER_CONTEXT,
   RENDERER_MAINTHREAD_CONTEXT,
   GPU_VIDEO_ACCELERATOR_CONTEXT,
   OFFSCREEN_VIDEO_CAPTURE_CONTEXT,
   OFFSCREEN_CONTEXT_FOR_WEBGL,
   CONTEXT_TYPE_UNKNOWN,
   OFFSCREEN_CONTEXT_FOR_TESTING = CONTEXT_TYPE_UNKNOWN,
 };
 
 std::string CommandBufferContextTypeToString(CommandBufferContextType type);
 
 void UmaRecordContextInitFailed(CommandBufferContextType type);
 
 void UmaRecordContextLost(CommandBufferContextType type,
                           gpu::error::Error error,
                           gpu::error::ContextLostReason reason);
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_GPU_CLIENT_COMMAND_BUFFER_METRICS_H_