Fix errors in display resolution change notifications

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 <utility>
 
 #include "ash/resources/grit/ash_resources.h"
 #include "ash/shell.h"
@@ skipping 144 matching lines @@
 ResolutionNotificationController::ResolutionNotificationController() {
   Shell::Get()->window_tree_host_manager()->AddObserver(this);
   display::Screen::GetScreen()->AddObserver(this);
 }
 
 ResolutionNotificationController::~ResolutionNotificationController() {
   Shell::Get()->window_tree_host_manager()->RemoveObserver(this);
   display::Screen::GetScreen()->RemoveObserver(this);
 }
 
-void ResolutionNotificationController::PrepareNotification(
+bool ResolutionNotificationController::PrepareNotificationAndSetDisplayMode(
     int64_t display_id,
     const scoped_refptr<display::ManagedDisplayMode>& old_resolution,
     const scoped_refptr<display::ManagedDisplayMode>& new_resolution,
     const base::Closure& accept_callback) {
   DCHECK(old_resolution);
   DCHECK(new_resolution);
 
-  DCHECK(!display::Display::IsInternalDisplayId(display_id));
+  display::DisplayManager* const display_manager =
+      Shell::Get()->display_manager();
+  if (display::Display::IsInternalDisplayId(display_id)) {
+    // We don't show notifications to confirm/revert the resolution change in
+    // the case of an internal display.
+    return display_manager->SetDisplayMode(display_id, new_resolution);
+  }
+
   // If multiple resolution changes are invoked for the same display,
   // the original resolution for the first resolution change has to be used
   // instead of the specified |old_resolution|.
   scoped_refptr<display::ManagedDisplayMode> original_resolution;
   if (change_info_ && change_info_->display_id == display_id) {
     DCHECK(change_info_->new_resolution->size() == old_resolution->size());
     original_resolution = change_info_->old_resolution;
   }
 
   if (change_info_ && change_info_->display_id != display_id) {
     // Preparing the notification for a new resolution change of another display
     // before the previous one was accepted. We decided that it's safer to
     // revert the previous resolution change since the user didn't explicitly
     // accept it, and we have no way of knowing for sure that it worked.
     RevertResolutionChange(false /* display_was_removed */);
   }
 
   change_info_.reset(new ResolutionChangeInfo(display_id, old_resolution,
                                               new_resolution, accept_callback));
   if (original_resolution && !original_resolution->size().IsEmpty())
     change_info_->old_resolution = original_resolution;
+
+  if (!display_manager->SetDisplayMode(display_id, new_resolution)) {
+    // Discard the prepared notification data since we failed to set the new
+    // resolution.
+    change_info_.reset();
+    return false;
+  }
+
+  return true;
 }
 
 bool ResolutionNotificationController::DoesNotificationTimeout() {
   return change_info_ && change_info_->timeout_count > 0;
 }
 
 void ResolutionNotificationController::CreateOrUpdateNotification(
     bool enable_spoken_feedback) {
   message_center::MessageCenter* message_center =
       message_center::MessageCenter::Get();
@@ skipping 121 matching lines @@
     change_info_->timer.Start(FROM_HERE, base::TimeDelta::FromSeconds(1), this,
                               &ResolutionNotificationController::OnTimerTick);
   }
 }
 
 void ResolutionNotificationController::SuppressTimerForTest() {
   g_use_timer = false;
 }
 
 }  // namespace ash