Replace FOR_EACH_OBSERVER in c/b/chromeos with range-based for

chrome/browser/chromeos/system/pointer_device_observer.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/chromeos/system/pointer_device_observer.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "chrome/browser/chromeos/system/input_device_settings.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 43 matching lines @@
                  weak_factory_.GetWeakPtr()));
 }
 
 void PointerDeviceObserver::CheckMouseExists() {
   InputDeviceSettings::Get()->MouseExists(
       base::Bind(&PointerDeviceObserver::OnMouseExists,
                  weak_factory_.GetWeakPtr()));
 }
 
 void PointerDeviceObserver::OnTouchpadExists(bool exists) {
-  FOR_EACH_OBSERVER(Observer, observers_, TouchpadExists(exists));
+  for (auto& observer : observers_)
+    observer.TouchpadExists(exists);
 }
 
 void PointerDeviceObserver::OnMouseExists(bool exists) {
-  FOR_EACH_OBSERVER(Observer, observers_, MouseExists(exists));
+  for (auto& observer : observers_)
+    observer.MouseExists(exists);
 }
 
 PointerDeviceObserver::Observer::~Observer() {
 }
 
 }  // namespace system
 }  // namespace chromeos