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

ui/compositor/layer_animation_sequence.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 "ui/compositor/layer_animation_sequence.h"
 
 #include <algorithm>
 #include <iterator>
 
 #include "base/trace_event/trace_event.h"
@@ skipping 214 matching lines @@
       LayerAnimationElement::ToAnimatableProperty(target_property);
   DCHECK(element_properties & event_property);
   elements_[current_index]->set_effective_start_time(monotonic_time);
 }
 
 void LayerAnimationSequence::OnScheduled() {
   NotifyScheduled();
 }
 
 void LayerAnimationSequence::OnAnimatorDestroyed() {
-  if (observers_.might_have_observers()) {
-    base::ObserverListBase<LayerAnimationObserver>::Iterator it(&observers_);
-    LayerAnimationObserver* obs;
-    while ((obs = it.GetNext()) != NULL) {
-      if (!obs->RequiresNotificationWhenAnimatorDestroyed()) {
-        // Remove the observer, but do not allow notifications to be sent.
-        observers_.RemoveObserver(obs);
-        obs->DetachedFromSequence(this, false);
-      }
+  for (LayerAnimationObserver& observer : observers_) {
+    if (!observer.RequiresNotificationWhenAnimatorDestroyed()) {
+      // Remove the observer, but do not allow notifications to be sent.
+      observers_.RemoveObserver(&observer);
+      observer.DetachedFromSequence(this, false);
     }
   }
 }
 
 size_t LayerAnimationSequence::size() const {
   return elements_.size();
 }
 
 LayerAnimationElement* LayerAnimationSequence::FirstElement() const {
   if (elements_.empty()) {
@@ skipping 28 matching lines @@
 
 LayerAnimationElement* LayerAnimationSequence::CurrentElement() const {
   if (elements_.empty())
     return NULL;
 
   size_t current_index = last_element_ % elements_.size();
   return elements_[current_index].get();
 }
 
 }  // namespace ui