Add support for injecting VideoBitrateAllocatorFactory also on IOS

This patch exposes webrtc::PeerConnectionDependencies c++-object
and makes it possible to supply one when creating a PeerConnection.

This makes it possible to e.g inject a VideoBitrateAllocatorFactory.

Bug: webrtc:10547
Change-Id: Ib7431bdcec1380e7903dc5f66f3583501aeab0a5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/168307
Commit-Queue: Jonas Oreland <jonaso@webrtc.org>
Reviewed-by: Anders Carlsson <andersc@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30480}

sdk/objc/api/peerconnection/RTCPeerConnection+Private.h

@@ -78,7 +78,17 @@ class PeerConnectionDelegateAdapter : public PeerConnectionObserver {
 - (instancetype)initWithFactory:(RTCPeerConnectionFactory *)factory
                   configuration:(RTCConfiguration *)configuration
                     constraints:(RTCMediaConstraints *)constraints
-                       delegate:(nullable id<RTCPeerConnectionDelegate>)delegate
+                       delegate:(nullable id<RTCPeerConnectionDelegate>)delegate;
+
+/** Initialize an RTCPeerConnection with a configuration, constraints,
+ *  delegate and PeerConnectionDependencies.
+ */
+- (instancetype)initWithDependencies:(RTCPeerConnectionFactory *)factory
+                       configuration:(RTCConfiguration *)configuration
+                         constraints:(RTCMediaConstraints *)constraints
+                        dependencies:
+                            (std::unique_ptr<webrtc::PeerConnectionDependencies>)dependencies
+                            delegate:(nullable id<RTCPeerConnectionDelegate>)delegate
     NS_DESIGNATED_INITIALIZER;
 
 + (webrtc::PeerConnectionInterface::SignalingState)nativeSignalingStateForState:

sdk/objc/api/peerconnection/RTCPeerConnection.mm

@@ -307,6 +307,23 @@ void PeerConnectionDelegateAdapter::OnRemoveTrack(
                     constraints:(RTCMediaConstraints *)constraints
                        delegate:(id<RTCPeerConnectionDelegate>)delegate {
   NSParameterAssert(factory);
+  std::unique_ptr<webrtc::PeerConnectionDependencies> dependencies =
+      std::make_unique<webrtc::PeerConnectionDependencies>(nullptr);
+  return [self initWithDependencies:factory
+                      configuration:configuration
+                        constraints:constraints
+                       dependencies:std::move(dependencies)
+                           delegate:delegate];
+}
+
+- (instancetype)initWithDependencies:(RTCPeerConnectionFactory *)factory
+                       configuration:(RTCConfiguration *)configuration
+                         constraints:(RTCMediaConstraints *)constraints
+                        dependencies:
+                            (std::unique_ptr<webrtc::PeerConnectionDependencies>)dependencies
+                            delegate:(id<RTCPeerConnectionDelegate>)delegate {
+  NSParameterAssert(factory);
+  NSParameterAssert(dependencies.get());
   std::unique_ptr<webrtc::PeerConnectionInterface::RTCConfiguration> config(
       [configuration createNativeConfiguration]);
   if (!config) {
@@ -315,13 +332,12 @@ void PeerConnectionDelegateAdapter::OnRemoveTrack(
   if (self = [super init]) {
     _observer.reset(new webrtc::PeerConnectionDelegateAdapter(self));
     _nativeConstraints = constraints.nativeConstraints;
-    CopyConstraintsIntoRtcConfiguration(_nativeConstraints.get(),
-                                        config.get());
-    _peerConnection =
-        factory.nativeFactory->CreatePeerConnection(*config,
-                                                    nullptr,
-                                                    nullptr,
-                                                    _observer.get());
+    CopyConstraintsIntoRtcConfiguration(_nativeConstraints.get(), config.get());
+
+    webrtc::PeerConnectionDependencies deps = std::move(*dependencies.release());
+    deps.observer = _observer.get();
+    _peerConnection = factory.nativeFactory->CreatePeerConnection(*config, std::move(deps));
+
     if (!_peerConnection) {
       return nil;
     }

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

@@ -22,6 +22,7 @@ class NetworkControllerFactoryInterface;
 class VideoEncoderFactory;
 class VideoDecoderFactory;
 class AudioProcessing;
+struct PeerConnectionDependencies;
 
 }  // namespace webrtc
 
@@ -87,6 +88,16 @@ NS_ASSUME_NONNULL_BEGIN
                         decoderFactory:(nullable id<RTCVideoDecoderFactory>)decoderFactory
                  mediaTransportFactory:
                      (std::unique_ptr<webrtc::MediaTransportFactory>)mediaTransportFactory;
+
+/** Initialize an RTCPeerConnection with a configuration, constraints, and
+ *  dependencies.
+ */
+- (RTCPeerConnection *)
+    peerConnectionWithDependencies:(RTCConfiguration *)configuration
+                       constraints:(RTCMediaConstraints *)constraints
+                      dependencies:(std::unique_ptr<webrtc::PeerConnectionDependencies>)dependencies
+                          delegate:(nullable id<RTCPeerConnectionDelegate>)delegate;
+
 @end
 
 NS_ASSUME_NONNULL_END

sdk/objc/api/peerconnection/RTCPeerConnectionFactory.mm

@@ -296,6 +296,18 @@
                                            delegate:delegate];
 }
 
+- (RTCPeerConnection *)
+    peerConnectionWithDependencies:(RTCConfiguration *)configuration
+                       constraints:(RTCMediaConstraints *)constraints
+                      dependencies:(std::unique_ptr<webrtc::PeerConnectionDependencies>)dependencies
+                          delegate:(id<RTCPeerConnectionDelegate>)delegate {
+  return [[RTCPeerConnection alloc] initWithDependencies:self
+                                           configuration:configuration
+                                             constraints:constraints
+                                            dependencies:std::move(dependencies)
+                                                delegate:delegate];
+}
+
 - (void)setOptions:(nonnull RTCPeerConnectionFactoryOptions *)options {
   RTC_DCHECK(options != nil);
   _nativeFactory->SetOptions(options.nativeOptions);