Add shortcut keys to ui scaling

ash/display/display_manager.h

 // 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.
 
 #ifndef ASH_DISPLAY_DISPLAY_MANAGER_H_
 #define ASH_DISPLAY_DISPLAY_MANAGER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 25 matching lines @@
 // TODO(oshima): gfx::Screen needs to return translated coordinates
 // if the root window is translated. crbug.com/119268.
 class ASH_EXPORT DisplayManager : public aura::RootWindowObserver {
  public:
   DisplayManager();
   virtual ~DisplayManager();
 
   // Used to emulate display change when run in a desktop environment instead
   // of on a device.
   static void CycleDisplay();
-  static void ToggleDisplayScale();
+  static void ToggleDisplayScaleFactor();
 
   // When set to true, the MonitorManager calls OnDisplayBoundsChanged
   // even if the display's bounds didn't change. Used to swap primary
   // display.
   void set_force_bounds_changed(bool force_bounds_changed) {
     force_bounds_changed_ = force_bounds_changed;
   }
 
   // Returns the display id of the first display in the outupt list.
   int64 first_display_id() const { return first_display_id_; }
@@ skipping 22 matching lines @@
   // that the insets size should be specified in DIP size. It also triggers the
   // display's bounds change.
   void SetOverscanInsets(int64 display_id, const gfx::Insets& insets_in_dip);
 
   // Clears the overscan insets
   void ClearCustomOverscanInsets(int64 display_id);
 
   // Sets the display's rotation.
   void SetDisplayRotation(int64 display_id, gfx::Display::Rotation rotation);
 
+  // Sets the display's ui scale.
+  void SetDisplayUIScale(int64 display_id, float ui_scale);
+
+  // Tells if display rotation/ui scaling features are enabled.
+  bool IsDisplayRotationEnabled() const;
+  bool IsDisplayUIScalingEnabled() const;
+
   // Returns the current overscan insets for the specified |display_id|.
   // Returns an empty insets (0, 0, 0, 0) if no insets are specified for
   // the display.
   gfx::Insets GetOverscanInsets(int64 display_id) const;
 
   // Called when display configuration has changed. The new display
   // configurations is passed as a vector of Display object, which
   // contains each display's new infomration.
   void OnNativeDisplaysChanged(
       const std::vector<DisplayInfo>& display_info_list);
@@ skipping 108 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(DisplayManager);
 };
 
 extern const aura::WindowProperty<int64>* const kDisplayIdKey;
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_DISPLAY_DISPLAY_MANAGER_H_