Wait for display configuration to finish before suspending

ui/display/chromeos/display_configurator.cc

 // 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.
 
 #include "ui/display/chromeos/display_configurator.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/sys_info.h"
@@ skipping 836 matching lines @@
 }
 
 void DisplayConfigurator::AddObserver(Observer* observer) {
   observers_.AddObserver(observer);
 }
 
 void DisplayConfigurator::RemoveObserver(Observer* observer) {
   observers_.RemoveObserver(observer);
 }
 
-void DisplayConfigurator::SuspendDisplays() {
+void DisplayConfigurator::SuspendDisplays(
+    const ConfigurationCallback& callback) {
   // If the display is off due to user inactivity and there's only a single
   // internal display connected, switch to the all-on state before
   // suspending.  This shouldn't be very noticeable to the user since the
   // backlight is off at this point, and doing this lets us resume directly
   // into the "on" state, which greatly reduces resume times.
   if (requested_power_state_ == chromeos::DISPLAY_POWER_ALL_OFF) {
     SetDisplayPower(chromeos::DISPLAY_POWER_ALL_ON,
-                    kSetDisplayPowerOnlyIfSingleInternalDisplay,
-                    base::Bind(&DoNothing));
+                    kSetDisplayPowerOnlyIfSingleInternalDisplay, callback);
 
     // We need to make sure that the monitor configuration we just did actually
     // completes before we return, because otherwise the X message could be
     // racing with the HandleSuspendReadiness message.
     native_display_delegate_->SyncWithServer();
+  } else {
+    callback.Run(true);
   }
 
   displays_suspended_ = true;
 
   // Stop |configure_timer_| because we will force probe and configure all the
   // displays at resume time anyway.
   configure_timer_.Stop();
 }
 
 void DisplayConfigurator::ResumeDisplays() {
@@ skipping 141 matching lines @@
     FOR_EACH_OBSERVER(
         Observer, observers_, OnDisplayModeChanged(cached_displays_));
   } else {
     FOR_EACH_OBSERVER(
         Observer, observers_, OnDisplayModeChangeFailed(cached_displays_,
                                                         attempted_state));
   }
 }
 
 }  // namespace ui