Add OnDisplayMetricsChanged in DisplayObserver.

chrome/browser/ui/webui/options/chromeos/display_overscan_handler.cc

 // Copyright (c) 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 "chrome/browser/ui/webui/options/chromeos/display_overscan_handler.h"
 
 #include <string>
 
 #include "ash/display/display_controller.h"
 #include "ash/screen_util.h"
@@ skipping 63 matching lines @@
   web_ui()->RegisterMessageCallback(
       "move",
       base::Bind(&DisplayOverscanHandler::HandleMove,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback(
       "resize",
       base::Bind(&DisplayOverscanHandler::HandleResize,
                  base::Unretained(this)));
 }
 
-void DisplayOverscanHandler::OnDisplayBoundsChanged(
-    const gfx::Display& display) {
-}
-
 void DisplayOverscanHandler::OnDisplayAdded(const gfx::Display& new_display) {
   web_ui()->CallJavascriptFunction(
       "options.DisplayOverscan.onOverscanCanceled");
 }
 
 void DisplayOverscanHandler::OnDisplayRemoved(const gfx::Display& old_display) {
   web_ui()->CallJavascriptFunction(
       "options.DisplayOverscan.onOverscanCanceled");
 }
 
+void DisplayOverscanHandler::OnDisplayMetricsChanged(const gfx::Display&,
+                                                     uint32_t) {
+}
+
 void DisplayOverscanHandler::HandleStart(const base::ListValue* args) {
   int64 display_id = gfx::Display::kInvalidDisplayID;
   std::string id_value;
   if (!args->GetString(0, &id_value)) {
     LOG(ERROR) << "Can't find ID";
     return;
   }
 
   if (!base::StringToInt64(id_value, &display_id) ||
       display_id == gfx::Display::kInvalidDisplayID) {
@@ skipping 86 matching lines @@
     LOG(ERROR) << "The orientation must be '" << kOrientationHorizontal
                << "' or '" << kOrientationVertical << "': "
                << orientation;
     return;
   }
   overscan_calibrator_->UpdateInsets(insets);
 }
 
 }  // namespace options
 }  // namespace chromeos