Revert of Add OnDisplayMetricsChanged in DisplayObserver.

ash/touch/touch_hud_debug.cc

Index: ash/touch/touch_hud_debug.cc
diff --git a/ash/touch/touch_hud_debug.cc b/ash/touch/touch_hud_debug.cc
index 20fab48588522cc2e61bc44186ee2d6108a32583..983d86bf36f7fef11586cc2b34bc42dcc9905e6c 100644
--- a/ash/touch/touch_hud_debug.cc
+++ b/ash/touch/touch_hud_debug.cc
@@ -465,11 +465,10 @@
   label_container_->SetSize(label_container_->GetPreferredSize());
 }
 
-void TouchHudDebug::OnDisplayMetricsChanged(const gfx::Display& display,
-                                            uint32_t metrics) {
-  TouchObserverHUD::OnDisplayMetricsChanged(display, metrics);
-
-  if (display.id() != display_id() || !(metrics & DISPLAY_METRIC_BOUNDS))
+void TouchHudDebug::OnDisplayBoundsChanged(const gfx::Display& display) {
+  TouchObserverHUD::OnDisplayBoundsChanged(display);
+
+  if (display.id() != display_id())
     return;
   const gfx::Size& size = display.size();
   canvas_->SetSize(size);