chromeos: Save display power state on config failure.

ui/display/chromeos/display_configurator.h

Index: ui/display/chromeos/display_configurator.h
diff --git a/ui/display/chromeos/display_configurator.h b/ui/display/chromeos/display_configurator.h
index c891478a7ee525be59b3ad25da6fbcb7f7a9656f..40a25e2aac9d5a1523200851e92ab50f4975b026 100644
--- a/ui/display/chromeos/display_configurator.h
+++ b/ui/display/chromeos/display_configurator.h
@@ -137,7 +137,9 @@ class DISPLAY_EXPORT DisplayConfigurator : public NativeDisplayObserver {
   virtual ~DisplayConfigurator();
 
   MultipleDisplayState display_state() const { return display_state_; }
-  chromeos::DisplayPowerState power_state() const { return power_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_;
@@ -320,8 +322,11 @@ class DISPLAY_EXPORT DisplayConfigurator : public NativeDisplayObserver {
 
   gfx::Size framebuffer_size_;
 
-  // The current power state.
-  chromeos::DisplayPowerState power_state_;
+  // The last-requested and current power state. These may differ if
+  // configuration fails: SetDisplayMode() needs the last-requested state while
+  // SetDisplayPower() needs the current state.
+  chromeos::DisplayPowerState requested_power_state_;
+  chromeos::DisplayPowerState current_power_state_;
 
   // Most-recently-used display configuration. Note that the actual
   // configuration changes asynchronously.