mus: Embedder can request and observe BeginFrame for embedded client.

ui/aura/window.cc

 // Copyright (c) 2012 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 "ui/aura/window.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <utility>
@@ skipping 981 matching lines @@
 }
 
 std::unique_ptr<cc::CompositorFrameSink> Window::CreateCompositorFrameSink() {
   return port_->CreateCompositorFrameSink();
 }
 
 cc::SurfaceId Window::GetSurfaceId() const {
   return port_->GetSurfaceId();
 }
 
+void Window::SetNeedsBeginFrames(bool needs, base::RepeatingClosure callback) {
+  port_->SetNeedsBeginFrames(needs, std::move(callback));
+}
+
 void Window::OnPaintLayer(const ui::PaintContext& context) {
   Paint(context);
 }
 
 void Window::OnDelegatedFrameDamage(const gfx::Rect& damage_rect_in_dip) {
   DCHECK(layer());
   for (WindowObserver& observer : observers_)
     observer.OnDelegatedFrameDamage(this, damage_rect_in_dip);
 }
 
@@ skipping 71 matching lines @@
     layer_name = "Unnamed Window";
 
   if (id_ != -1)
     layer_name += " " + base::IntToString(id_);
 
   layer()->set_name(layer_name);
 #endif
 }
 
 }  // namespace aura