gpu: Move GpuWatchdogThread into //gpu/ipc/service from content.

services/ui/gpu/gpu_service_internal.h

Index: services/ui/gpu/gpu_service_internal.h
diff --git a/services/ui/gpu/gpu_service_internal.h b/services/ui/gpu/gpu_service_internal.h
index a720b06e6013f43c1f1f39d94363ef913e21b25c..9a453e06396334251c16074535b393240658e69d 100644
--- a/services/ui/gpu/gpu_service_internal.h
+++ b/services/ui/gpu/gpu_service_internal.h
@@ -30,6 +30,7 @@ struct DefaultSingletonTraits;
 namespace gpu {
 class GpuChannelHost;
 class GpuMemoryBufferFactory;
+class GpuWatchdogThread;
 class SyncPointManager;
 }
 
@@ -137,6 +138,8 @@ class GpuServiceInternal : public gpu::GpuChannelManagerDelegate,
   // The thread that handles IO events for GpuService.
   base::Thread io_thread_;
 
+  scoped_refptr<gpu::GpuWatchdogThread> watchdog_thread_;
+
   std::unique_ptr<gpu::SyncPointManager> owned_sync_point_manager_;
 
   std::unique_ptr<gpu::GpuChannelManager> gpu_channel_manager_;