mus: Notify the client whether adding an accelerator was successful.

components/mus/ws/window_tree_host_impl.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 COMPONENTS_MUS_WS_WINDOW_TREE_HOST_IMPL_H_
 #define COMPONENTS_MUS_WS_WINDOW_TREE_HOST_IMPL_H_
 
 #include <queue>
 
 #include "base/macros.h"
@@ skipping 79 matching lines @@
   void DestroyFocusController();
 
   void UpdateTextInputState(ServerWindow* window,
                             const ui::TextInputState& state);
   void SetImeVisibility(ServerWindow* window, bool visible);
 
   // WindowTreeHost:
   void SetSize(mojo::SizePtr size) override;
   void SetTitle(const mojo::String& title) override;
   void AddAccelerator(uint32_t id,
-                      mojom::EventMatcherPtr event_matcher) override;
+                      mojom::EventMatcherPtr event_matcher,
+                      const AddAcceleratorCallback& callback) override;
   void RemoveAccelerator(uint32_t id) override;
   void AddActivationParent(uint32_t window_id) override;
   void RemoveActivationParent(uint32_t window_id) override;
   void ActivateNextWindow() override;
   void SetUnderlaySurfaceOffsetAndExtendedHitArea(
       Id window_id,
       int32_t x_offset,
       int32_t y_offset,
       mojo::InsetsPtr hit_area) override;
 
@@ skipping 56 matching lines @@
   std::queue<mojom::EventPtr> event_queue_;
   base::OneShotTimer event_ack_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHostImpl);
 };
 
 }  // namespace ws
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_WS_WINDOW_TREE_HOST_IMPL_H_