Revert of Add OnDisplayMetricsChanged in DisplayObserver.

ash/display/resolution_notification_controller.cc

Index: ash/display/resolution_notification_controller.cc
diff --git a/ash/display/resolution_notification_controller.cc b/ash/display/resolution_notification_controller.cc
index 315dd5ab5b65cb512ba195cf4f9c1d231443ac29..2c454029e79d7ef4332407487358a78d00a4289e 100644
--- a/ash/display/resolution_notification_controller.cc
+++ b/ash/display/resolution_notification_controller.cc
@@ -285,6 +285,10 @@
       display_id, old_resolution);
 }
 
+void ResolutionNotificationController::OnDisplayBoundsChanged(
+    const gfx::Display& display) {
+}
+
 void ResolutionNotificationController::OnDisplayAdded(
     const gfx::Display& new_display) {
 }
@@ -293,10 +297,6 @@
     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() {