Adds ability for pre-target accelerators to not consume events

ash/mus/window_manager.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 ASH_MUS_WINDOW_MANAGER_H_
 #define ASH_MUS_WINDOW_MANAGER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 82 matching lines @@
   bool OnWmSetProperty(
       ::ui::Window* window,
       const std::string& name,
       std::unique_ptr<std::vector<uint8_t>>* new_data) override;
   ::ui::Window* OnWmCreateTopLevelWindow(
       std::map<std::string, std::vector<uint8_t>>* properties) override;
   void OnWmClientJankinessChanged(const std::set<::ui::Window*>& client_windows,
                                   bool not_responding) override;
   void OnWmNewDisplay(::ui::Window* window,
                       const display::Display& display) override;
-  void OnAccelerator(uint32_t id, const ui::Event& event) override;
+  ui::mojom::EventResult OnAccelerator(uint32_t id,
+                                       const ui::Event& event) override;
 
   shell::Connector* connector_;
 
   ::ui::WindowTreeClient* window_tree_client_ = nullptr;
 
   ::ui::WindowManagerClient* window_manager_client_ = nullptr;
 
   std::unique_ptr<ShadowController> shadow_controller_;
 
   std::set<std::unique_ptr<RootWindowController>> root_window_controllers_;
 
   base::ObserverList<WindowManagerObserver> observers_;
 
   std::unique_ptr<display::Screen> screen_;
 
   std::unique_ptr<WmShellMus> shell_;
 
   std::unique_ptr<WmLookupMus> lookup_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowManager);
 };
 
 }  // namespace mus
 }  // namespace ash
 
 #endif  // ASH_MUS_WINDOW_MANAGER_H_