Make a clean interface for dialog callbacks.

chrome/browser/ui/app_modal_dialogs/app_modal_dialog_queue.cc

 // Copyright (c) 2011 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/ui/app_modal_dialogs/app_modal_dialog_queue.h"
 
 #include "base/memory/singleton.h"
 
 void AppModalDialogQueue::AddDialog(AppModalDialog* dialog) {
   if (!active_dialog_) {
     ShowModalDialog(dialog);
     return;
   }
-  app_modal_dialog_queue_.push(dialog);
+  app_modal_dialog_queue_.push_back(dialog);
 }
 
 void AppModalDialogQueue::ShowNextDialog() {
   AppModalDialog* dialog = GetNextDialog();
   if (dialog)
     ShowModalDialog(dialog);
   else
     active_dialog_ = NULL;
 }
 
@@ skipping 28 matching lines @@
   // that.
   active_dialog_ = dialog;
   showing_modal_dialog_ = true;
   dialog->ShowModalDialog();
   showing_modal_dialog_ = false;
 }
 
 AppModalDialog* AppModalDialogQueue::GetNextDialog() {
   while (!app_modal_dialog_queue_.empty()) {
     AppModalDialog* dialog = app_modal_dialog_queue_.front();
-    app_modal_dialog_queue_.pop();
+    app_modal_dialog_queue_.pop_front();
     if (dialog->IsValid())
       return dialog;
     delete dialog;
   }
   return NULL;
 }