Rewrite most of the scopers in //base/mac to use ScopedTypeRef or ScopedGeneric.

ui/accelerated_widget_mac/display_link_mac.cc

 // Copyright 2014 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/accelerated_widget_mac/display_link_mac.h"
 
 #include <stdint.h>
 
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/trace_event/trace_event.h"
 
 namespace base {
 
 template<>
 struct ScopedTypeRefTraits<CVDisplayLinkRef> {
   static CVDisplayLinkRef InvalidValue() { return nullptr; }
-  static void Retain(CVDisplayLinkRef object) {
-    CVDisplayLinkRetain(object);
+  static CVDisplayLinkRef Retain(CVDisplayLinkRef object) {
+    return CVDisplayLinkRetain(object);
   }
   static void Release(CVDisplayLinkRef object) {
     CVDisplayLinkRelease(object);
   }
 };
 
 }  // namespace base
 
 namespace ui {
 
@@ skipping 159 matching lines @@
   DisplayLinkMac* display_link_mac = found->second;
   display_link_mac->timebase_and_interval_valid_ = false;
 }
 
 // static
 base::LazyInstance<DisplayLinkMac::DisplayMap>
     DisplayLinkMac::display_map_ = LAZY_INSTANCE_INITIALIZER;
 
 }  // ui