Add OnDisplayMetricsChanged in DisplayObserver.

ash/display/resolution_notification_controller.cc

 // Copyright 2013 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 "ash/display/resolution_notification_controller.h"
 
 #include "ash/display/display_controller.h"
 #include "ash/display/display_manager.h"
 #include "ash/shell.h"
 #include "ash/system/system_notifier.h"
@@ skipping 267 matching lines @@
 void ResolutionNotificationController::RevertResolutionChange() {
   message_center::MessageCenter::Get()->RemoveNotification(
       kNotificationId, false /* by_user */);
   int64 display_id = change_info_->display_id;
   gfx::Size old_resolution = change_info_->old_resolution;
   change_info_.reset();
   Shell::GetInstance()->display_manager()->SetDisplayResolution(
       display_id, old_resolution);
 }
 
-void ResolutionNotificationController::OnDisplayBoundsChanged(
-    const gfx::Display& display) {
-}
-
 void ResolutionNotificationController::OnDisplayAdded(
     const gfx::Display& new_display) {
 }
 
 void ResolutionNotificationController::OnDisplayRemoved(
     const gfx::Display& old_display) {
   if (change_info_ && change_info_->display_id == old_display.id())
     RevertResolutionChange();
 }
 
+void ResolutionNotificationController::OnDisplayMetricsChanged(
+    const gfx::Display&, uint32_t) {
+}
+
 void ResolutionNotificationController::OnDisplayConfigurationChanged() {
   if (!change_info_)
     return;
 
   const DisplayInfo& info = Shell::GetInstance()->display_manager()->
       GetDisplayInfo(change_info_->display_id);
   change_info_->current_resolution = info.bounds_in_native().size();
   CreateOrUpdateNotification(true);
   if (g_use_timer && change_info_->timeout_count > 0) {
     change_info_->timer.Start(FROM_HERE,
                               base::TimeDelta::FromSeconds(1),
                               this,
                               &ResolutionNotificationController::OnTimerTick);
   }
 }
 
 void ResolutionNotificationController::SuppressTimerForTest() {
   g_use_timer = false;
 }
 
 }  // namespace ash