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

content/renderer/render_frame_impl.cc

 // Copyright 2013 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 "content/renderer/render_frame_impl.h"
 
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 1488 matching lines @@
     return false;
 
   // TODO(kenrb): document() should not be null, but as a transitional step
   // we have RenderFrameProxy 'wrapping' a RenderFrameImpl, passing messages
   // to this method. This happens for a top-level remote frame, where a
   // document-less RenderFrame is replaced by a RenderFrameProxy but kept
   // around and is still able to receive messages.
   if (!frame_->document().isNull())
     GetContentClient()->SetActiveURL(frame_->document().url());
 
-  base::ObserverListBase<RenderFrameObserver>::Iterator it(&observers_);
-  RenderFrameObserver* observer;
-  while ((observer = it.GetNext()) != NULL) {
-    if (observer->OnMessageReceived(msg))
+  for (auto& observer : observers_) {
+    if (observer.OnMessageReceived(msg))
       return true;
   }
 
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(RenderFrameImpl, msg)
     IPC_MESSAGE_HANDLER(FrameMsg_Navigate, OnNavigate)
     IPC_MESSAGE_HANDLER(FrameMsg_BeforeUnload, OnBeforeUnload)
     IPC_MESSAGE_HANDLER(FrameMsg_SwapOut, OnSwapOut)
     IPC_MESSAGE_HANDLER(FrameMsg_Delete, OnDeleteFrame)
     IPC_MESSAGE_HANDLER(FrameMsg_Stop, OnStop)
@@ skipping 5017 matching lines @@
   // event target. Potentially a Pepper plugin will receive the event.
   // In order to tell whether a plugin gets the last mouse event and which it
   // is, we set |pepper_last_mouse_event_target_| to null here. If a plugin gets
   // the event, it will notify us via DidReceiveMouseEvent() and set itself as
   // |pepper_last_mouse_event_target_|.
   pepper_last_mouse_event_target_ = nullptr;
 #endif
 }
 
 }  // namespace content