mus: Rename GpuService to Gpu.

services/ui/gpu/gpu_main.h

Index: services/ui/gpu/gpu_main.h
diff --git a/services/ui/gpu/gpu_main.h b/services/ui/gpu/gpu_main.h
index bd03dde2b1f434ac8ee4747f30a18935c12ce669..694b717f74050a2e178ec119d84f9aee5c71a949 100644
--- a/services/ui/gpu/gpu_main.h
+++ b/services/ui/gpu/gpu_main.h
@@ -82,10 +82,10 @@ class GpuMain : public gpu::GpuSandboxHelper, public mojom::GpuMain {
 
   std::unique_ptr<gpu::GpuMemoryBufferFactory> gpu_memory_buffer_factory_;
 
-  // The main thread for GpuService.
+  // The main thread for Gpu.
   base::Thread gpu_thread_;
 
-  // The thread that handles IO events for GpuService.
+  // The thread that handles IO events for Gpu.
   base::Thread io_thread_;
 
   // The display compositor gets its own thread in mus-gpu. The gpu service,