chromeos: Add power supply info reading capability

chrome/browser/chromeos/status/status_area_view_chromeos.cc

 // Copyright (c) 2011 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/chromeos/status/status_area_view_chromeos.h"
 
 #include "base/command_line.h"
 #include "chrome/browser/chromeos/cros/cros_library.h"
 #include "chrome/browser/chromeos/status/accessibility_menu_button.h"
 #include "chrome/browser/chromeos/status/caps_lock_menu_button.h"
@@ skipping 15 matching lines @@
 StatusAreaViewChromeos::~StatusAreaViewChromeos() {
   CrosLibrary::Get()->GetPowerLibrary()->RemoveObserver(this);
   system::TimezoneSettings::GetInstance()->RemoveObserver(this);
 }
 
 void StatusAreaViewChromeos::Init(StatusAreaButton::Delegate* delegate,
                                   ScreenMode screen_mode) {
   AddChromeosButtons(this, delegate, screen_mode);
 }
 
-void StatusAreaViewChromeos::PowerChanged(const PowerSupplyStatus& status) {
-}
-
 void StatusAreaViewChromeos::SystemResumed() {
   UpdateClockText();
 }
 
 void StatusAreaViewChromeos::TimezoneChanged(const icu::TimeZone& timezone) {
   UpdateClockText();
 }
 
 void StatusAreaViewChromeos::UpdateClockText() {
   ClockMenuButton* clock_button =
@@ skipping 26 matching lines @@
   status_area->AddButton(new ClockMenuButton(delegate), border);
 
   status_area->AddButton(
       new InputMethodMenuButton(delegate, screen_mode), no_border);
   status_area->AddButton(
       new NetworkMenuButton(delegate, screen_mode), no_border);
   status_area->AddButton(new PowerMenuButton(delegate), no_border);
 }
 
 }  // namespace chromeos