Add FrameEncryptor/FrameDecryptor support to Objective C API for WebRTC.

This change adds bindings so that native FrameEncryptor and native FrameDecryptor
objects can be set on the objective C RTCRtpSender and RTCRtpReceiver objects.

Bug: webrtc:9681
Change-Id: Iec4006ea020d6ab6adcc0ad068dcd8fb2738063d
Reviewed-on: https://webrtc-review.googlesource.com/c/103020
Commit-Queue: Benjamin Wright <benwright@webrtc.org>
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Reviewed-by: Anders Carlsson <andersc@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24936}

sdk/objc/api/peerconnection/RTCRtpReceiver+Native.h

@@ -0,0 +1,30 @@
+/*
+ *  Copyright 2018 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.
+ */
+
+#import "RTCRtpReceiver.h"
+
+#include "api/crypto/framedecryptorinterface.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ * This class extension exposes methods that work directly with injectable C++ components.
+ */
+@interface RTCRtpReceiver ()
+
+/** Sets a user defined frame decryptor that will decrypt the entire frame.
+ * This will decrypt the entire frame using the user provided decryption
+ * mechanism regardless of whether SRTP is enabled or not.
+ */
+- (void)setFrameDecryptor:(rtc::scoped_refptr<webrtc::FrameDecryptorInterface>)frameDecryptor;
+
+@end
+
+NS_ASSUME_NONNULL_END

sdk/objc/api/peerconnection/RTCRtpReceiver.mm

@@ -12,6 +12,7 @@
 
 #import "RTCMediaStreamTrack+Private.h"
 #import "RTCRtpParameters+Private.h"
+#import "RTCRtpReceiver+Native.h"
 #import "base/RTCLogging.h"
 #import "helpers/NSString+StdString.h"
 
@@ -97,6 +98,12 @@ void RtpReceiverDelegateAdapter::OnFirstPacketReceived(
   return (NSUInteger)_nativeRtpReceiver.get();
 }
 
+#pragma mark - Native
+
+- (void)setFrameDecryptor:(rtc::scoped_refptr<webrtc::FrameDecryptorInterface>)frameDecryptor {
+  _nativeRtpReceiver->SetFrameDecryptor(frameDecryptor);
+}
+
 #pragma mark - Private
 
 - (rtc::scoped_refptr<webrtc::RtpReceiverInterface>)nativeRtpReceiver {

sdk/objc/api/peerconnection/RTCRtpSender+Native.h

@@ -0,0 +1,31 @@
+/*
+ *  Copyright 2018 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.
+ */
+
+#import "RTCRtpSender.h"
+
+#include "api/crypto/frameencryptorinterface.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ * This class extension exposes methods that work directly with injectable C++ components.
+ */
+@interface RTCRtpSender ()
+
+/** Sets a defined frame encryptor that will encrypt the entire frame
+ * before it is sent across the network. This will encrypt the entire frame
+ * using the user provided encryption mechanism regardless of whether SRTP is
+ * enabled or not.
+ */
+- (void)setFrameEncryptor:(rtc::scoped_refptr<webrtc::FrameEncryptorInterface>)frameEncryptor;
+
+@end
+
+NS_ASSUME_NONNULL_END

sdk/objc/api/peerconnection/RTCRtpSender.mm

@@ -13,6 +13,7 @@
 #import "RTCDtmfSender+Private.h"
 #import "RTCMediaStreamTrack+Private.h"
 #import "RTCRtpParameters+Private.h"
+#import "RTCRtpSender+Native.h"
 #import "base/RTCLogging.h"
 #import "helpers/NSString+StdString.h"
 
@@ -79,6 +80,12 @@
   return (NSUInteger)_nativeRtpSender.get();
 }
 
+#pragma mark - Native
+
+- (void)setFrameEncryptor:(rtc::scoped_refptr<webrtc::FrameEncryptorInterface>)frameEncryptor {
+  _nativeRtpSender->SetFrameEncryptor(frameEncryptor);
+}
+
 #pragma mark - Private
 
 - (rtc::scoped_refptr<webrtc::RtpSenderInterface>)nativeRtpSender {