Switch ObserverList::size() to ObserverList::might_have_observers() Pt.1

chrome/browser/status_icons/status_icon.cc

 // Copyright (c) 2012 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/status_icons/status_icon.h"
 
 #include "chrome/browser/status_icons/status_icon_observer.h"
 #include "ui/base/models/menu_model.h"
 
 StatusIcon::StatusIcon() {
 }
 
 StatusIcon::~StatusIcon() {
 }
 
 void StatusIcon::AddObserver(StatusIconObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void StatusIcon::RemoveObserver(StatusIconObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 bool StatusIcon::HasObservers() const {
-  return observers_.size() > 0;
+  return observers_.might_have_observers();
 }
 
 void StatusIcon::DispatchClickEvent() {
   FOR_EACH_OBSERVER(StatusIconObserver, observers_, OnStatusIconClicked());
 }
 
 #if defined(OS_WIN)
 void StatusIcon::DispatchBalloonClickEvent() {
   FOR_EACH_OBSERVER(StatusIconObserver, observers_, OnBalloonClicked());
 }
 #endif
 
 void StatusIcon::SetContextMenu(ui::MenuModel* menu) {
   // The UI may been showing a menu for the current model, don't destroy it
   // until we've notified the UI of the change.
   scoped_ptr<ui::MenuModel> old_menu = context_menu_contents_.Pass();
   context_menu_contents_.reset(menu);
   UpdatePlatformContextMenu(menu);
 }