ObjC: Implement HW codecs in ObjC instead of C++

The current ObjC HW encoder is implemented as a C++
webrtc::VideoEncoder. We then wrap it two times in the following way:
webrtc::VideoEncoder -> RTCVideoEncoder -> webrtc::VideoEncoder.
This was originally done to minimize the code diff when landing the
injectable encoder.

This CL removes the first wrapping and implements the ObjC HW encoder
as a RTCVideoEncoder directly. Similarly, the decoder is implemented
as a RTCVideoDecoder directly.

Based on andersc@ CL: https://codereview.webrtc.org/2978623002/.

BUG=webrtc:7924

Review-Url: https://codereview.webrtc.org/2987413002
Cr-Commit-Position: refs/heads/master@{#19255}

webrtc/modules/video_coding/codecs/test/objc_codec_h264_test.h

@@ -0,0 +1,26 @@
+/*
+ *  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_MODULES_VIDEO_CODING_CODECS_TEST_OBJC_CODEC_H264_TEST_H_
+#define WEBRTC_MODULES_VIDEO_CODING_CODECS_TEST_OBJC_CODEC_H264_TEST_H_
+
+#include <memory>
+
+#include "webrtc/media/engine/webrtcvideodecoderfactory.h"
+#include "webrtc/media/engine/webrtcvideoencoderfactory.h"
+
+namespace webrtc {
+
+std::unique_ptr<cricket::WebRtcVideoEncoderFactory> CreateObjCEncoderFactory();
+std::unique_ptr<cricket::WebRtcVideoDecoderFactory> CreateObjCDecoderFactory();
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_VIDEO_CODING_CODECS_TEST_OBJC_CODEC_H264_TEST_H_

webrtc/modules/video_coding/codecs/test/objc_codec_h264_test.mm

@@ -0,0 +1,29 @@
+/*
+ *  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.
+ */
+
+#include "webrtc/modules/video_coding/codecs/test/objc_codec_h264_test.h"
+
+#import "WebRTC/RTCVideoCodecH264.h"
+#include "webrtc/sdk/objc/Framework/Classes/VideoToolbox/objc_video_decoder_factory.h"
+#include "webrtc/sdk/objc/Framework/Classes/VideoToolbox/objc_video_encoder_factory.h"
+
+namespace webrtc {
+
+std::unique_ptr<cricket::WebRtcVideoEncoderFactory> CreateObjCEncoderFactory() {
+  return std::unique_ptr<cricket::WebRtcVideoEncoderFactory>(
+      new ObjCVideoEncoderFactory([[RTCVideoEncoderFactoryH264 alloc] init]));
+}
+
+std::unique_ptr<cricket::WebRtcVideoDecoderFactory> CreateObjCDecoderFactory() {
+  return std::unique_ptr<cricket::WebRtcVideoDecoderFactory>(
+      new ObjCVideoDecoderFactory([[RTCVideoDecoderFactoryH264 alloc] init]));
+}
+
+}  // namespace webrtc

webrtc/modules/video_coding/codecs/test/videoprocessor_integrationtest.h

@@ -23,8 +23,7 @@
 #include "webrtc/sdk/android/src/jni/androidmediadecoder_jni.h"
 #include "webrtc/sdk/android/src/jni/androidmediaencoder_jni.h"
 #elif defined(WEBRTC_IOS)
-#include "webrtc/sdk/objc/Framework/Classes/VideoToolbox/decoder.h"
-#include "webrtc/sdk/objc/Framework/Classes/VideoToolbox/encoder.h"
+#include "webrtc/modules/video_coding/codecs/test/objc_codec_h264_test.h"
 #endif
 
 #include "webrtc/media/engine/webrtcvideodecoderfactory.h"
@@ -178,9 +177,13 @@ class VideoProcessorIntegrationTest : public testing::Test {
 #elif defined(WEBRTC_IOS)
       ASSERT_EQ(kVideoCodecH264, config_.codec_settings->codecType)
           << "iOS HW codecs only support H264.";
-      encoder_.reset(new H264VideoToolboxEncoder(
-          cricket::VideoCodec(cricket::kH264CodecName)));
-      decoder_.reset(new H264VideoToolboxDecoder());
+      std::unique_ptr<cricket::WebRtcVideoEncoderFactory> encoder_factory =
+          CreateObjCEncoderFactory();
+      std::unique_ptr<cricket::WebRtcVideoDecoderFactory> decoder_factory =
+          CreateObjCDecoderFactory();
+      cricket::VideoCodec codecInfo = encoder_factory->supported_codecs().at(0);
+      encoder_.reset(encoder_factory->CreateVideoEncoder(codecInfo));
+      decoder_.reset(decoder_factory->CreateVideoDecoder(kVideoCodecH264));
 #else
       RTC_NOTREACHED() << "Only support HW codecs on Android and iOS.";
 #endif