Remove usage of base::ObserverList<T>::Iter::GetNext() in //ui.

ui/views/mus/pointer_watcher_event_router.cc

 // Copyright 2016 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 "ui/views/mus/pointer_watcher_event_router.h"
 
 #include "services/ui/public/cpp/window.h"
 #include "services/ui/public/cpp/window_tree_client.h"
 #include "ui/display/screen.h"
 #include "ui/events/base_event_utils.h"
 #include "ui/events/event.h"
 #include "ui/views/mus/native_widget_mus.h"
 #include "ui/views/pointer_watcher.h"
 
 namespace views {
 namespace {
 
 bool HasPointerWatcher(
     base::ObserverList<views::PointerWatcher, true>* observer_list) {
-  if (!observer_list->might_have_observers())
-    return false;
-
-  // might_have_observers() returned true, see if there really are any
-  // observers. The only way to truly know is to use an Iterator and see if it
-  // has at least one observer.
-  base::ObserverList<PointerWatcher>::Iterator iterator(observer_list);
-  return !!iterator.GetNext();
+  return observer_list->begin() != observer_list->end();
 }
 
 }  // namespace
 
 PointerWatcherEventRouter::PointerWatcherEventRouter(
     ui::WindowTreeClient* client)
     : window_tree_client_(client) {
   client->AddObserver(this);
 }
 
@@ skipping 105 matching lines @@
 void PointerWatcherEventRouter::OnDidDestroyClient(
     ui::WindowTreeClient* client) {
   // We expect that all observers have been removed by this time.
   DCHECK_EQ(event_types_, EventTypes::NONE);
   DCHECK_EQ(client, window_tree_client_);
   window_tree_client_->RemoveObserver(this);
   window_tree_client_ = nullptr;
 }
 
 }  // namespace views