Add a new GetInstance() method for singleton classes used in chrome/browser files.

chrome/browser/ui/app_modal_dialogs/app_modal_dialog_queue.cc

Index: chrome/browser/ui/app_modal_dialogs/app_modal_dialog_queue.cc
diff --git a/chrome/browser/ui/app_modal_dialogs/app_modal_dialog_queue.cc b/chrome/browser/ui/app_modal_dialogs/app_modal_dialog_queue.cc
index c29abe0603d6eb37984e00bc9c8ad48b189609a2..924f7c0a093b2a7a87d73d95c420f37d46942a7d 100644
--- a/chrome/browser/ui/app_modal_dialogs/app_modal_dialog_queue.cc
+++ b/chrome/browser/ui/app_modal_dialogs/app_modal_dialog_queue.cc
@@ -38,6 +38,11 @@ AppModalDialogQueue::AppModalDialogQueue()
 
 AppModalDialogQueue::~AppModalDialogQueue() {}
 
+// static
+AppModalDialogQueue* AppModalDialogQueue::GetInstance() {
+  return Singleton<AppModalDialogQueue>::get();
+}
+
 void AppModalDialogQueue::ShowModalDialog(AppModalDialog* dialog) {
   // Be sure and set the active_dialog_ field first, otherwise if
   // ShowModalDialog triggers a call back to the queue they'll get the old