Create experimental Obj-C++ API.

This can be used to wrap Objective-C components in C++ classes, so users
can use the WebRTC C++ API directly together with the iOS specific
components provided by our SDK.

Bug: webrtc:8832
Change-Id: I6d34f7ec62d51df8d3a5340a2e17d30ae73e13e8
Reviewed-on: https://webrtc-review.googlesource.com/46162
Commit-Queue: Anders Carlsson <andersc@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21850}
diff --git a/sdk/objc/Framework/Classes/PeerConnection/RTCPeerConnectionFactory.mm b/sdk/objc/Framework/Classes/PeerConnection/RTCPeerConnectionFactory.mm
index ec9d16c..e304068 100644
--- a/sdk/objc/Framework/Classes/PeerConnection/RTCPeerConnectionFactory.mm
+++ b/sdk/objc/Framework/Classes/PeerConnection/RTCPeerConnectionFactory.mm
@@ -24,8 +24,6 @@
 #import "WebRTC/RTCLogging.h"
 #import "WebRTC/RTCVideoCodecFactory.h"
 #ifndef HAVE_NO_MEDIA
-#include "VideoToolbox/objc_video_decoder_factory.h"
-#include "VideoToolbox/objc_video_encoder_factory.h"
 #import "WebRTC/RTCVideoCodecH264.h"
 // The no-media version PeerConnectionFactory doesn't depend on these files, but the gn check tool
 // is not smart enough to take the #ifdef into account.
@@ -34,6 +32,11 @@
 #include "media/engine/convert_legacy_video_factory.h"          // nogncheck
 #include "modules/audio_device/include/audio_device.h"          // nogncheck
 #include "modules/audio_processing/include/audio_processing.h"  // nogncheck
+
+#include "sdk/objc/Framework/Native/api/video_decoder_factory.h"
+#include "sdk/objc/Framework/Native/api/video_encoder_factory.h"
+#include "sdk/objc/Framework/Native/src/objc_video_decoder_factory.h"
+#include "sdk/objc/Framework/Native/src/objc_video_encoder_factory.h"
 #endif
 
 #include "Video/objcvideotracksource.h"
@@ -61,15 +64,16 @@
 #elif !defined(USE_BUILTIN_SW_CODECS)
   return [self initWithNativeAudioEncoderFactory:webrtc::CreateBuiltinAudioEncoderFactory()
                        nativeAudioDecoderFactory:webrtc::CreateBuiltinAudioDecoderFactory()
-                       nativeVideoEncoderFactory:std::unique_ptr<webrtc::VideoEncoderFactory>(
-                                                     new webrtc::ObjCVideoEncoderFactory(
-                                                         [[RTCVideoEncoderFactoryH264 alloc] init]))
-                       nativeVideoDecoderFactory:std::unique_ptr<webrtc::VideoDecoderFactory>(
-                                                     new webrtc::ObjCVideoDecoderFactory(
-                                                         [[RTCVideoDecoderFactoryH264 alloc] init]))
+                       nativeVideoEncoderFactory:webrtc::ObjCToNativeVideoEncoderFactory(
+                                                     [[RTCVideoEncoderFactoryH264 alloc] init])
+                       nativeVideoDecoderFactory:webrtc::ObjCToNativeVideoDecoderFactory(
+                                                     [[RTCVideoDecoderFactoryH264 alloc] init])
                                audioDeviceModule:nullptr
                            audioProcessingModule:nullptr];
 #else
+  // Here we construct webrtc::ObjCVideoEncoderFactory directly because we rely
+  // on the fact that they inherit from both webrtc::VideoEncoderFactory and
+  // cricket::WebRtcVideoEncoderFactory.
   return [self initWithNativeAudioEncoderFactory:webrtc::CreateBuiltinAudioEncoderFactory()
                        nativeAudioDecoderFactory:webrtc::CreateBuiltinAudioDecoderFactory()
                  legacyNativeVideoEncoderFactory:new webrtc::ObjCVideoEncoderFactory(
@@ -89,10 +93,10 @@
   std::unique_ptr<webrtc::VideoEncoderFactory> native_encoder_factory;
   std::unique_ptr<webrtc::VideoDecoderFactory> native_decoder_factory;
   if (encoderFactory) {
-    native_encoder_factory.reset(new webrtc::ObjCVideoEncoderFactory(encoderFactory));
+    native_encoder_factory = webrtc::ObjCToNativeVideoEncoderFactory(encoderFactory);
   }
   if (decoderFactory) {
-    native_decoder_factory.reset(new webrtc::ObjCVideoDecoderFactory(decoderFactory));
+    native_decoder_factory = webrtc::ObjCToNativeVideoDecoderFactory(decoderFactory);
   }
   return [self initWithNativeAudioEncoderFactory:webrtc::CreateBuiltinAudioEncoderFactory()
                        nativeAudioDecoderFactory:webrtc::CreateBuiltinAudioDecoderFactory()
diff --git a/sdk/objc/Framework/Classes/PeerConnection/RTCVideoCodecH264.mm b/sdk/objc/Framework/Classes/PeerConnection/RTCVideoCodecH264.mm
index f862453..402e09f 100644
--- a/sdk/objc/Framework/Classes/PeerConnection/RTCVideoCodecH264.mm
+++ b/sdk/objc/Framework/Classes/PeerConnection/RTCVideoCodecH264.mm
@@ -16,7 +16,6 @@
 #import "WebRTC/RTCVideoCodec.h"
 
 #include "rtc_base/timeutils.h"
-#include "sdk/objc/Framework/Classes/Video/objc_frame_buffer.h"
 #include "system_wrappers/include/field_trial.h"
 
 const char kHighProfileExperiment[] = "WebRTC-H264HighProfile";
diff --git a/sdk/objc/Framework/Classes/PeerConnection/RTCVideoFrame+Private.h b/sdk/objc/Framework/Classes/PeerConnection/RTCVideoFrame+Private.h
index 43d3fbf..7fd2247 100644
--- a/sdk/objc/Framework/Classes/PeerConnection/RTCVideoFrame+Private.h
+++ b/sdk/objc/Framework/Classes/PeerConnection/RTCVideoFrame+Private.h
@@ -13,7 +13,6 @@
 #import "WebRTC/RTCVideoFrameBuffer.h"
 
 #include "api/video/video_frame.h"
-#include "sdk/objc/Framework/Classes/Video/objc_frame_buffer.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
diff --git a/sdk/objc/Framework/Classes/PeerConnection/RTCVideoFrame.mm b/sdk/objc/Framework/Classes/PeerConnection/RTCVideoFrame.mm
index 19dd245..f5d7195 100644
--- a/sdk/objc/Framework/Classes/PeerConnection/RTCVideoFrame.mm
+++ b/sdk/objc/Framework/Classes/PeerConnection/RTCVideoFrame.mm
@@ -15,6 +15,8 @@
 
 #include "api/video/video_frame.h"
 #include "rtc_base/timeutils.h"
+#include "sdk/objc/Framework/Native/api/video_frame_buffer.h"
+#include "sdk/objc/Framework/Native/src/objc_frame_buffer.h"
 
 id<RTCVideoFrameBuffer> nativeToRtcFrameBuffer(
     const rtc::scoped_refptr<webrtc::VideoFrameBuffer> &buffer) {
@@ -104,7 +106,7 @@
 
 - (webrtc::VideoFrame)nativeVideoFrame {
   rtc::scoped_refptr<webrtc::VideoFrameBuffer> frameBuffer =
-      new rtc::RefCountedObject<webrtc::ObjCFrameBuffer>(self.buffer);
+      webrtc::ObjCToNativeVideoFrameBuffer(self.buffer);
   webrtc::VideoFrame videoFrame(frameBuffer,
                                 (webrtc::VideoRotation)self.rotation,
                                 self.timeStampNs / rtc::kNumNanosecsPerMicrosec);
diff --git a/sdk/objc/Framework/Classes/PeerConnection/RTCVideoRendererAdapter.mm b/sdk/objc/Framework/Classes/PeerConnection/RTCVideoRendererAdapter.mm
index 79cc1a7..639d060 100644
--- a/sdk/objc/Framework/Classes/PeerConnection/RTCVideoRendererAdapter.mm
+++ b/sdk/objc/Framework/Classes/PeerConnection/RTCVideoRendererAdapter.mm
@@ -13,7 +13,6 @@
 #import "RTCVideoRendererAdapter+Private.h"
 #import "WebRTC/RTCVideoFrame.h"
 #import "WebRTC/RTCVideoFrameBuffer.h"
-#import "objc_frame_buffer.h"
 
 #include <memory>