Add OnDisplayMetricsChanged in DisplayObserver.

ash/touch/touch_hud_debug.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/touch/touch_hud_debug.h"
 
 #include "ash/display/display_manager.h"
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
 #include "base/json/json_string_value_serializer.h"
@@ skipping 447 matching lines @@
 void TouchHudDebug::OnTouchEvent(ui::TouchEvent* event) {
   if (event->touch_id() >= kMaxTouchPoints)
     return;
 
   touch_log_->AddTouchPoint(*event);
   canvas_->TouchPointAdded(event->touch_id());
   UpdateTouchPointLabel(event->touch_id());
   label_container_->SetSize(label_container_->GetPreferredSize());
 }
 
-void TouchHudDebug::OnDisplayBoundsChanged(const gfx::Display& display) {
-  TouchObserverHUD::OnDisplayBoundsChanged(display);
+void TouchHudDebug::OnDisplayMetricsChanged(const gfx::Display& display,
+                                            uint32_t metrics) {
+  TouchObserverHUD::OnDisplayMetricsChanged(display, metrics);
 
-  if (display.id() != display_id())
+  if (display.id() != display_id() || !(metrics & DISPLAY_METRIC_BOUNDS))
     return;
   const gfx::Size& size = display.size();
   canvas_->SetSize(size);
   label_container_->SetY(size.height() / kReducedScale);
 }
 
 void TouchHudDebug::SetHudForRootWindowController(
     RootWindowController* controller) {
   controller->set_touch_hud_debug(this);
 }
 
 void TouchHudDebug::UnsetHudForRootWindowController(
     RootWindowController* controller) {
   controller->set_touch_hud_debug(NULL);
 }
 
 }  // namespace ash