Reusing base::IdType<...> to implement SurfaceId.

components/mus/surfaces/top_level_display_client.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/mus/surfaces/top_level_display_client.h"
 
 #include "base/thread_task_runner_handle.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/surfaces/display.h"
@@ skipping 15 matching lines @@
 }
 }
 
 TopLevelDisplayClient::TopLevelDisplayClient(
     gfx::AcceleratedWidget widget,
     const scoped_refptr<GpuState>& gpu_state,
     const scoped_refptr<SurfacesState>& surfaces_state)
     : task_runner_(base::ThreadTaskRunnerHandle::Get()),
       surfaces_state_(surfaces_state),
       factory_(surfaces_state->manager(), this),
-      cc_id_(static_cast<uint64_t>(surfaces_state->next_id_namespace()) << 32) {
+      cc_id_(cc::SurfaceId::FromUnsafeValue(
+          static_cast<uint64_t>(surfaces_state->next_id_namespace()) << 32)) {
   factory_.Create(cc_id_);
 
   display_.reset(new cc::Display(this, surfaces_state_->manager(), nullptr,
                                  nullptr, cc::RendererSettings()));
 
   scoped_ptr<cc::OutputSurface> output_surface =
       make_scoped_ptr(new DirectOutputSurface(
           new SurfacesContextProvider(this, widget, gpu_state)));
 
   int max_frames_pending = output_surface->capabilities().max_frames_pending;
@@ skipping 65 matching lines @@
   // TODO(fsamuel): Implement this.
 }
 
 void TopLevelDisplayClient::SetBeginFrameSource(
     cc::SurfaceId surface_id,
     cc::BeginFrameSource* begin_frame_source) {
   // TODO(tansell): Implement this.
 }
 
 }  // namespace mus