Revert of services/ui: Have an explicit lifetime/ownership of ui::GpuService.

content/renderer/render_thread_impl.h

Index: content/renderer/render_thread_impl.h
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 6dfbfead2c1cc0777b489fdac9b1fc3aa29f6da2..bb0553c620455017b2a7aa54c4080c15dea061a7 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -86,10 +86,6 @@
 
 namespace scheduler {
 class WebThreadBase;
-}
-
-namespace ui {
-class GpuService;
 }
 
 namespace v8 {
@@ -660,10 +656,6 @@
   std::unique_ptr<memory_coordinator::ChildMemoryCoordinatorImpl>
       memory_coordinator_;
 
-#if defined(MOJO_SHELL_CLIENT)
-  std::unique_ptr<ui::GpuService> gpu_service_;
-#endif
-
   scoped_refptr<base::SingleThreadTaskRunner>
       main_thread_compositor_task_runner_;