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

ui/events/platform/platform_event_source.cc

Index: ui/events/platform/platform_event_source.cc
diff --git a/ui/events/platform/platform_event_source.cc b/ui/events/platform/platform_event_source.cc
index a33562693abce3b5516a70848e7b9faa77316afa..dfab7fce76648ffdcc00fc592dbd262625eef83c 100644
--- a/ui/events/platform/platform_event_source.cc
+++ b/ui/events/platform/platform_event_source.cc
@@ -75,12 +75,10 @@ uint32_t PlatformEventSource::DispatchEvent(PlatformEvent platform_event) {
   if (overridden_dispatcher_)
     action = overridden_dispatcher_->DispatchEvent(platform_event);
 
-  if ((action & POST_DISPATCH_PERFORM_DEFAULT) &&
-      dispatchers_.might_have_observers()) {
-    base::ObserverList<PlatformEventDispatcher>::Iterator iter(&dispatchers_);
-    while (PlatformEventDispatcher* dispatcher = iter.GetNext()) {
-      if (dispatcher->CanDispatchEvent(platform_event))
-        action = dispatcher->DispatchEvent(platform_event);
+  if (action & POST_DISPATCH_PERFORM_DEFAULT) {
+    for (PlatformEventDispatcher& dispatcher : dispatchers_) {
+      if (dispatcher.CanDispatchEvent(platform_event))
+        action = dispatcher.DispatchEvent(platform_event);
       if (action & POST_DISPATCH_STOP_PROPAGATION)
         break;
     }