Revert of gpu: GPU service scheduler.

services/ui/gpu/gpu_service.h

Index: services/ui/gpu/gpu_service.h
diff --git a/services/ui/gpu/gpu_service.h b/services/ui/gpu/gpu_service.h
index be59f4bcb1a35e71028717bc1dc707b55791aa0c..f07519bb66312c6f3bc65ba66714bbaeb9f84506 100644
--- a/services/ui/gpu/gpu_service.h
+++ b/services/ui/gpu/gpu_service.h
@@ -29,7 +29,6 @@
 namespace gpu {
 class GpuMemoryBufferFactory;
 class GpuWatchdogThread;
-class Scheduler;
 class SyncPointManager;
 }
 
@@ -182,8 +181,6 @@
   std::unique_ptr<gpu::SyncPointManager> owned_sync_point_manager_;
   gpu::SyncPointManager* sync_point_manager_ = nullptr;
 
-  std::unique_ptr<gpu::Scheduler> scheduler_;
-
   // An event that will be signalled when we shutdown. On some platforms it
   // comes from external sources.
   std::unique_ptr<base::WaitableEvent> owned_shutdown_event_;