Impl mus::mojom::GpuService to enable using Chrome IPC version gpu CmdBuf in mus

ui/views/mus/surface_binding.cc

Index: ui/views/mus/surface_binding.cc
diff --git a/ui/views/mus/surface_binding.cc b/ui/views/mus/surface_binding.cc
index a3dc98fb7304f2ad4a5c85cb9b99d714bc5ce0fe..72fa2ad86fe50d2723bb65a3bcd0bcfdd34ce17f 100644
--- a/ui/views/mus/surface_binding.cc
+++ b/ui/views/mus/surface_binding.cc
@@ -20,6 +20,7 @@
 #include "cc/output/software_output_device.h"
 #include "cc/resources/shared_bitmap_manager.h"
 #include "components/mus/public/cpp/context_provider.h"
+#include "components/mus/public/cpp/gpu_service.h"
 #include "components/mus/public/cpp/output_surface.h"
 #include "components/mus/public/cpp/window.h"
 #include "components/mus/public/cpp/window_tree_connection.h"
@@ -100,13 +101,18 @@ SurfaceBinding::PerConnectionState::CreateOutputSurface(
     mus::mojom::SurfaceType surface_type) {
   if (gpu_.encountered_error())
     return nullptr;
-  // TODO(sky): figure out lifetime here. Do I need to worry about the return
-  // value outliving this?
-  mus::mojom::CommandBufferPtr cb;
-  gpu_->CreateOffscreenGLES2Context(GetProxy(&cb));
-
+  mojo::ScopedMessagePipeHandle scoped_handle;
+  if (!mus::GpuService::UseChromeGpuCommandBuffer()) {
+    // TODO(sky): figure out lifetime here. Do I need to worry about the return
+    // value outliving this?
+    mus::mojom::CommandBufferPtr cb;
+    gpu_->CreateOffscreenGLES2Context(GetProxy(&cb));
+    scoped_handle = cb.PassInterface().PassHandle();
+  } else {
+    mus::GpuService::Initialize(connector_);
+  }
   scoped_refptr<cc::ContextProvider> context_provider(
-      new mus::ContextProvider(cb.PassInterface().PassHandle()));
+      new mus::ContextProvider(std::move(scoped_handle)));
   return base::WrapUnique(new mus::OutputSurface(
       context_provider, window->RequestSurface(surface_type)));
 }