On resume perform a delayed call to SetDisplayPower()

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>
@@ skipping 99 matching lines @@
   };
 
   // Helper class used by tests.
   class TestApi {
    public:
     TestApi(DisplayConfigurator* configurator) : configurator_(configurator) {}
     ~TestApi() {}
 
     // If |configure_timer_| is started, stops the timer, runs
     // ConfigureDisplays(), and returns true; returns false otherwise.
-    bool TriggerConfigureTimeout();
+    bool TriggerConfigureTimeout() WARN_UNUSED_RESULT;
 
    private:
     DisplayConfigurator* configurator_;  // not owned
 
     DISALLOW_COPY_AND_ASSIGN(TestApi);
   };
 
   // Flags that can be passed to SetDisplayPower().
-  static const int kSetDisplayPowerNoFlags = 0;
+  static const int kSetDisplayPowerNoFlags;
   // Configure displays even if the passed-in state matches |power_state_|.
-  static const int kSetDisplayPowerForceProbe = 1 << 0;
+  static const int kSetDisplayPowerForceProbe;
   // Do not change the state if multiple displays are connected or if the
   // only connected display is external.
-  static const int kSetDisplayPowerOnlyIfSingleInternalDisplay = 1 << 1;
+  static const int kSetDisplayPowerOnlyIfSingleInternalDisplay;
 
   // Gap between screens so cursor at bottom of active display doesn't
   // partially appear on top of inactive display. Higher numbers guard
   // against larger cursors, but also waste more memory.
   // For simplicity, this is hard-coded to avoid the complexity of always
   // determining the DPI of the screen and rationalizing which screen we
   // need to use for the DPI calculation.
   // See crbug.com/130188 for initial discussion.
   static const int kVerticalGap = 60;
 
@@ skipping 196 matching lines @@
 
   // The current power state.
   chromeos::DisplayPowerState power_state_;
 
   // Most-recently-used display configuration. Note that the actual
   // configuration changes asynchronously.
   DisplayStateList cached_displays_;
 
   ObserverList<Observer> observers_;
 
-  // The timer to delay configuring displays. See also the comments in
-  // Dispatch().
-  scoped_ptr<base::OneShotTimer<DisplayConfigurator> > configure_timer_;
+  // The timer to delay configuring displays. This is used to aggregate multiple
+  // display configuration events when they are reported in short time spans.
+  // See comment for NativeDisplayEventDispatcherX11 for more details.
+  base::OneShotTimer<DisplayConfigurator> configure_timer_;
 
   // Id for next display protection client.
   ContentProtectionClientId next_display_protection_client_id_;
 
   // Display protection requests of each client.
   ProtectionRequests client_protection_requests_;
 
   DISALLOW_COPY_AND_ASSIGN(DisplayConfigurator);
 };
 
 }  // namespace ui
 
 #endif  // UI_DISPLAY_CHROMEOS_DISPLAY_CONFIGURATOR_H_