Make ui::DisplayConfigurator a singleton

ui/display/chromeos/display_configurator.h

 // Copyright 2014 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_DISPLAY_CHROMEOS_DISPLAY_CONFIGURATOR_H_
 #define UI_DISPLAY_CHROMEOS_DISPLAY_CONFIGURATOR_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/event_types.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/singleton.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/timer/timer.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
 #include "ui/display/display_export.h"
 #include "ui/display/types/display_constants.h"
 #include "ui/display/types/native_display_observer.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace gfx {
 class Point;
 class Size;
 }
 
 namespace ui {
 struct DisplayConfigureRequest;
 class DisplayMode;
 class DisplaySnapshot;
 class NativeDisplayDelegate;
 class UpdateDisplayConfigurationTask;
 
+namespace test {
+class DisplayConfiguratorTest;
+}  // namespace test
+
 // This class interacts directly with the system display configurator.
 class DISPLAY_EXPORT DisplayConfigurator : public NativeDisplayObserver {
  public:
   typedef uint64_t ContentProtectionClientId;
   static const ContentProtectionClientId kInvalidClientId = 0;
 
   typedef base::Callback<void(bool)> ConfigurationCallback;
 
   struct DisplayState {
     DisplayState();
@@ skipping 121 matching lines @@
   // need to use for the DPI calculation.
   // See crbug.com/130188 for initial discussion.
   static const int kVerticalGap = 60;
 
   // Returns the mode within |display| that matches the given size with highest
   // refresh rate. Returns None if no matching display was found.
   static const DisplayMode* FindDisplayModeMatchingSize(
       const DisplaySnapshot& display,
       const gfx::Size& size);
 
-  DisplayConfigurator();
-  ~DisplayConfigurator() override;
-
   MultipleDisplayState display_state() const { return current_display_state_; }
   chromeos::DisplayPowerState requested_power_state() const {
     return requested_power_state_;
   }
   const gfx::Size framebuffer_size() const { return framebuffer_size_; }
   const std::vector<DisplayState>& cached_displays() const {
     return cached_displays_;
   }
 
   // Called when an external process no longer needs to control the display
@@ skipping 89 matching lines @@
 
   // Checks the available color profiles for |display_id| and fills the result
   // into |profiles|.
   std::vector<ui::ColorCalibrationProfile> GetAvailableColorCalibrationProfiles(
       int64_t display_id);
 
   // Updates the color calibration to |new_profile|.
   bool SetColorCalibrationProfile(int64_t display_id,
                                   ui::ColorCalibrationProfile new_profile);
 
+  // static
+  static DisplayConfigurator* GetInstance();
+
  private:
+  friend struct DefaultSingletonTraits<DisplayConfigurator>;
+  friend class ui::test::DisplayConfiguratorTest;
   class DisplayLayoutManagerImpl;
 
+  DisplayConfigurator();
+  ~DisplayConfigurator() override;
+
   // Mapping a display_id to a protection request bitmask.
   typedef std::map<int64_t, uint32_t> ContentProtections;
   // Mapping a client to its protection request.
   typedef std::map<ContentProtectionClientId, ContentProtections>
       ProtectionRequests;
 
   // Performs platform specific delegate initialization.
   scoped_ptr<NativeDisplayDelegate> CreatePlatformNativeDisplayDelegate();
 
   // Configures displays. Invoked by |configure_timer_|.
@@ skipping 122 matching lines @@
 
   // This must be the last variable.
   base::WeakPtrFactory<DisplayConfigurator> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DisplayConfigurator);
 };
 
 }  // namespace ui
 
 #endif  // UI_DISPLAY_CHROMEOS_DISPLAY_CONFIGURATOR_H_