[mus]Add FrameGenerator::SetHighContrastMode(bool)

services/ui/ws/display_manager.h

 // Copyright 2016 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 SERVICES_UI_WS_DISPLAY_MANAGER_H_
 #define SERVICES_UI_WS_DISPLAY_MANAGER_H_
 
 #include <map>
 #include <memory>
 #include <set>
@@ skipping 63 matching lines @@
     return !displays_.empty() || !pending_displays_.empty();
   }
 
   // Returns the id for the next root window (both for the root of a Display
   // as well as the root of WindowManagers).
   WindowId GetAndAdvanceNextRootId();
 
   // Called when the AcceleratedWidget is available for |display|.
   void OnDisplayAcceleratedWidgetAvailable(Display* display);
 
+  // Switch the high contrast mode of all Displays to |enabled|.
+  void SetHighContrastMode(bool enabled);
+
  private:
   // UserIdTrackerObserver:
   void OnActiveUserIdChanged(const UserId& previously_active_id,
                              const UserId& active_id) override;
 
   // display::ScreenManagerDelegate:
   void OnDisplayAdded(const display::Display& display,
                       const display::ViewportMetrics& metrics) override;
   void OnDisplayRemoved(int64_t id) override;
   void OnDisplayModified(const display::Display& display,
@@ skipping 16 matching lines @@
   // ID to use for next root node.
   ClientSpecificId next_root_id_;
 
   DISALLOW_COPY_AND_ASSIGN(DisplayManager);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_DISPLAY_MANAGER_H_