Reland of Injectable Obj-C video codecs

webrtc/sdk/objc/Framework/Classes/VideoToolbox/objc_video_decoder_factory.h

+/*
+ *  Copyright 2017 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.
+ */
+
+#ifndef WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_PEERCONNECTION_OBJC_VIDEO_DECODER_FACTORY_H_
+#define WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_PEERCONNECTION_OBJC_VIDEO_DECODER_FACTORY_H_
+
+#include "webrtc/media/base/codec.h"
+#include "webrtc/media/engine/webrtcvideodecoderfactory.h"
+
+@protocol RTCVideoDecoderFactory;
+
+namespace webrtc {
+
+class ObjCVideoDecoderFactory : public cricket::WebRtcVideoDecoderFactory {
+ public:
+  explicit ObjCVideoDecoderFactory(id<RTCVideoDecoderFactory>);
+  ~ObjCVideoDecoderFactory();
+
+  id<RTCVideoDecoderFactory> wrapped_decoder_factory() const;
+
+  webrtc::VideoDecoder* CreateVideoDecoder(
+      webrtc::VideoCodecType type) override;
+  void DestroyVideoDecoder(webrtc::VideoDecoder* decoder) override;
+
+ private:
+  id<RTCVideoDecoderFactory> decoder_factory_;
+  std::vector<cricket::VideoCodec> supported_codecs_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_PEERCONNECTION_OBJC_VIDEO_DECODER_FACTORY_H_