Reland of Add a webrtc{en,de}coderfactory implementation for VideoToolbox

webrtc/modules/video_coding/codecs/h264/h264_objc.mm

-/*
- *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- *
- */
-
-#include "webrtc/modules/video_coding/codecs/h264/include/h264.h"
-
-#if defined(WEBRTC_IOS)
-#import <UIKit/UIKit.h>
-#endif
-
-namespace webrtc {
-
-bool IsH264CodecSupportedObjC() {
-#if defined(WEBRTC_VIDEO_TOOLBOX_SUPPORTED) && \
-    defined(WEBRTC_IOS)
-  // Supported on iOS8+.
-  return [[[UIDevice currentDevice] systemVersion] doubleValue] >= 8.0;
-#else
-  // TODO(tkchin): Support OS/X once we stop mixing libstdc++ and libc++ on
-  // OSX 10.9.
-  return false;
-#endif
-}
-
-}  // namespace webrtc