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

ui/aura/test/mus/test_window_tree.h

 // 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.
 
 #ifndef UI_AURA_TEST_MUS_TEST_WINDOW_TREE_H_
 #define UI_AURA_TEST_MUS_TEST_WINDOW_TREE_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 107 matching lines @@
       uint32_t change_id,
       uint32_t window_id,
       const std::unordered_map<std::string, std::vector<uint8_t>>& properties)
       override;
   void DeleteWindow(uint32_t change_id, uint32_t window_id) override;
   void SetWindowBounds(
       uint32_t change_id,
       uint32_t window_id,
       const gfx::Rect& bounds,
       const base::Optional<cc::LocalSurfaceId>& local_surface_id) override;
+  void RequestBeginFrames(Id window_id,
+                          cc::mojom::FrameSinkObserverPtr observer) override;
   void SetClientArea(uint32_t window_id,
                      const gfx::Insets& insets,
                      const base::Optional<std::vector<gfx::Rect>>&
                          additional_client_areas) override;
   void SetHitTestMask(uint32_t window_id,
                       const base::Optional<gfx::Rect>& mask) override;
   void SetCanAcceptDrops(uint32_t window_id, bool accepts_drags) override;
   void SetWindowVisibility(uint32_t change_id,
                            uint32_t window_id,
                            bool visible) override;
@@ skipping 95 matching lines @@
   base::Optional<gfx::Rect> last_hit_test_mask_;
 
   base::Optional<cc::LocalSurfaceId> last_local_surface_id_;
 
   DISALLOW_COPY_AND_ASSIGN(TestWindowTree);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_TEST_MUS_TEST_WINDOW_TREE_H_