Restore type attributes and remove extraneous nullability annotations for Objective-C Mac build

BUG=webrtc:5592
R=tkchin@webrtc.org

Review URL: https://codereview.webrtc.org/1773743002 .

Patch from Jon Hjelle <hjon@andyet.net>.

Cr-Commit-Position: refs/heads/master@{#11922}
diff --git a/webrtc/api/objc/RTCConfiguration.h b/webrtc/api/objc/RTCConfiguration.h
index ed4bfc2..144c8d3 100644
--- a/webrtc/api/objc/RTCConfiguration.h
+++ b/webrtc/api/objc/RTCConfiguration.h
@@ -12,8 +12,6 @@
 
 @class RTCIceServer;
 
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
-
 /**
  * Represents the ice transport policy. This exposes the same states in C++,
  * which include one more state than what exists in the W3C spec.
@@ -55,8 +53,7 @@
 @interface RTCConfiguration : NSObject
 
 /** An array of Ice Servers available to be used by ICE. */
-@property(nonatomic, copy, nonnull) NSArray *iceServers;
-// @property(nonatomic, copy) NSArray<RTCIceServer *> *iceServers;
+@property(nonatomic, copy) NSArray<RTCIceServer *> *iceServers;
 
 /** Which candidates the ICE agent is allowed to use. The W3C calls it
  * |iceTransportPolicy|, while in C++ it is called |type|. */
@@ -75,7 +72,7 @@
 /** Key type used to generate SSL identity. Default is ECDSA. */
 @property(nonatomic, assign) RTCEncryptionKeyType keyType;
 
-- (nonnull instancetype)init NS_DESIGNATED_INITIALIZER;
+- (instancetype)init NS_DESIGNATED_INITIALIZER;
 
 @end
 
diff --git a/webrtc/api/objc/RTCIceCandidate.h b/webrtc/api/objc/RTCIceCandidate.h
index f7e27c2..41ea69e 100644
--- a/webrtc/api/objc/RTCIceCandidate.h
+++ b/webrtc/api/objc/RTCIceCandidate.h
@@ -11,7 +11,6 @@
 #import <Foundation/Foundation.h>
 
 NS_ASSUME_NONNULL_BEGIN
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
 
 @interface RTCIceCandidate : NSObject
 
@@ -28,16 +27,16 @@
 @property(nonatomic, readonly) NSInteger sdpMLineIndex;
 
 /** The SDP string for this candidate. */
-@property(nonatomic, readonly, nonnull) NSString *sdp;
+@property(nonatomic, readonly) NSString *sdp;
 
-- (nonnull instancetype)init NS_UNAVAILABLE;
+- (instancetype)init NS_UNAVAILABLE;
 
 /**
  * Initialize an RTCIceCandidate from SDP.
  */
-- (nonnull instancetype)initWithSdp:(nonnull NSString *)sdp
-                      sdpMLineIndex:(NSInteger)sdpMLineIndex
-                             sdpMid:(nullable NSString *)sdpMid
+- (instancetype)initWithSdp:(NSString *)sdp
+              sdpMLineIndex:(NSInteger)sdpMLineIndex
+                     sdpMid:(nullable NSString *)sdpMid
     NS_DESIGNATED_INITIALIZER;
 
 @end
diff --git a/webrtc/api/objc/RTCIceServer.h b/webrtc/api/objc/RTCIceServer.h
index 8ca179f..487588e 100644
--- a/webrtc/api/objc/RTCIceServer.h
+++ b/webrtc/api/objc/RTCIceServer.h
@@ -11,13 +11,11 @@
 #import <Foundation/Foundation.h>
 
 NS_ASSUME_NONNULL_BEGIN
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
 
 @interface RTCIceServer : NSObject
 
 /** URI(s) for this server represented as NSStrings. */
-@property(nonatomic, readonly, nonnull) NSArray *urlStrings;
-// @property(nonatomic, readonly) NSArray<NSString *> *urlStrings;
+@property(nonatomic, readonly) NSArray<NSString *> *urlStrings;
 
 /** Username to use if this RTCIceServer object is a TURN server. */
 @property(nonatomic, readonly, nullable) NSString *username;
@@ -28,17 +26,15 @@
 - (nonnull instancetype)init NS_UNAVAILABLE;
 
 /** Convenience initializer for a server with no authentication (e.g. STUN). */
-- (nonnull instancetype)initWithURLStrings:(nonnull NSArray *)urlStrings;
-// - (instancetype)initWithURLStrings:(NSArray<NSString *> *)urlStrings;
+- (instancetype)initWithURLStrings:(NSArray<NSString *> *)urlStrings;
 
 /**
  * Initialize an RTCIceServer with its associated URLs, optional username,
  * optional credential, and credentialType.
  */
-- (nonnull instancetype)initWithURLStrings:(nonnull NSArray *)urlStrings
-// - (instancetype)initWithURLStrings:(NSArray<NSString *> *)urlStrings
-                                  username:(nullable NSString *)username
-                                credential:(nullable NSString *)credential
+- (instancetype)initWithURLStrings:(NSArray<NSString *> *)urlStrings
+                          username:(nullable NSString *)username
+                        credential:(nullable NSString *)credential
     NS_DESIGNATED_INITIALIZER;
 
 @end
diff --git a/webrtc/api/objc/RTCIceServer.mm b/webrtc/api/objc/RTCIceServer.mm
index 9fc2154..95c380e 100644
--- a/webrtc/api/objc/RTCIceServer.mm
+++ b/webrtc/api/objc/RTCIceServer.mm
@@ -14,22 +14,19 @@
 #import "webrtc/base/objc/NSString+StdString.h"
 
 @implementation RTCIceServer
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
 
 @synthesize urlStrings = _urlStrings;
 @synthesize username = _username;
 @synthesize credential = _credential;
 
-- (instancetype)initWithURLStrings:(NSArray *)urlStrings {
-// - (instancetype)initWithURLStrings:(NSArray<NSString *> *)urlStrings {
+- (instancetype)initWithURLStrings:(NSArray<NSString *> *)urlStrings {
   NSParameterAssert(urlStrings.count);
   return [self initWithURLStrings:urlStrings
                          username:nil
                        credential:nil];
 }
 
-- (instancetype)initWithURLStrings:(NSArray *)urlStrings
-// - (instancetype)initWithURLStrings:(NSArray<NSString *> *)urlStrings
+- (instancetype)initWithURLStrings:(NSArray<NSString *> *)urlStrings
                           username:(NSString *)username
                         credential:(NSString *)credential {
   NSParameterAssert(urlStrings.count);
diff --git a/webrtc/api/objc/RTCMediaConstraints+Private.h b/webrtc/api/objc/RTCMediaConstraints+Private.h
index 84966d1..fa582ec 100644
--- a/webrtc/api/objc/RTCMediaConstraints+Private.h
+++ b/webrtc/api/objc/RTCMediaConstraints+Private.h
@@ -13,8 +13,6 @@
 #include "webrtc/api/mediaconstraintsinterface.h"
 #include "webrtc/base/scoped_ptr.h"
 
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
-
 namespace webrtc {
 
 class MediaConstraints : public MediaConstraintsInterface {
@@ -48,8 +46,7 @@
 /** Return a native Constraints object representing these constraints */
 + (webrtc::MediaConstraintsInterface::Constraints)
     nativeConstraintsForConstraints:
-        (NSDictionary *)constraints;
-        // (NSDictionary<NSString *, NSString *> *)constraints;
+        (NSDictionary<NSString *, NSString *> *)constraints;
 
 @end
 
diff --git a/webrtc/api/objc/RTCMediaConstraints.h b/webrtc/api/objc/RTCMediaConstraints.h
index 1ed456c..a8ad391 100644
--- a/webrtc/api/objc/RTCMediaConstraints.h
+++ b/webrtc/api/objc/RTCMediaConstraints.h
@@ -11,23 +11,17 @@
 #import <Foundation/Foundation.h>
 
 NS_ASSUME_NONNULL_BEGIN
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
 
 @interface RTCMediaConstraints : NSObject
 
-- (nonnull instancetype)init NS_UNAVAILABLE;
+- (instancetype)init NS_UNAVAILABLE;
 
 /** Initialize with mandatory and/or optional constraints. */
-- (nonnull instancetype)initWithMandatoryConstraints:
-    (nullable NSDictionary *)mandatory
-                                 optionalConstraints:
-    (nullable NSDictionary *)optional
+- (instancetype)initWithMandatoryConstraints:
+    (nullable NSDictionary<NSString *, NSString *> *)mandatory
+                         optionalConstraints:
+    (nullable NSDictionary<NSString *, NSString *> *)optional
     NS_DESIGNATED_INITIALIZER;
-// - (instancetype)initWithMandatoryConstraints:
-//     (nullable NSDictionary<NSString *, NSString *> *)mandatory
-//                          optionalConstraints:
-//     (nullable NSDictionary<NSString *, NSString *> *)optional
-//     NS_DESIGNATED_INITIALIZER;
 
 @end
 
diff --git a/webrtc/api/objc/RTCMediaConstraints.mm b/webrtc/api/objc/RTCMediaConstraints.mm
index 9d4e391..bf50668 100644
--- a/webrtc/api/objc/RTCMediaConstraints.mm
+++ b/webrtc/api/objc/RTCMediaConstraints.mm
@@ -13,8 +13,6 @@
 #import "webrtc/api/objc/RTCMediaConstraints+Private.h"
 #import "webrtc/base/objc/NSString+StdString.h"
 
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
-
 namespace webrtc {
 
 MediaConstraints::~MediaConstraints() {}
@@ -40,18 +38,14 @@
 
 
 @implementation RTCMediaConstraints {
-  NSDictionary *_mandatory;
-  // NSDictionary<NSString *, NSString *> *_mandatory;
-  NSDictionary *_optional;
-  // NSDictionary<NSString *, NSString *> *_optional;
+  NSDictionary<NSString *, NSString *> *_mandatory;
+  NSDictionary<NSString *, NSString *> *_optional;
 }
 
 - (instancetype)initWithMandatoryConstraints:
-    (NSDictionary *)mandatory
-    // (NSDictionary<NSString *, NSString *> *)mandatory
+    (NSDictionary<NSString *, NSString *> *)mandatory
                          optionalConstraints:
-    (NSDictionary *)optional {
-    // (NSDictionary<NSString *, NSString *> *)optional {
+    (NSDictionary<NSString *, NSString *> *)optional {
   if (self = [super init]) {
     _mandatory = [[NSDictionary alloc] initWithDictionary:mandatory
                                                 copyItems:YES];
@@ -82,8 +76,7 @@
 
 + (webrtc::MediaConstraintsInterface::Constraints)
     nativeConstraintsForConstraints:
-        (NSDictionary *)constraints {
-        // (NSDictionary<NSString *, NSString *> *)constraints {
+        (NSDictionary<NSString *, NSString *> *)constraints {
   webrtc::MediaConstraintsInterface::Constraints nativeConstraints;
   for (NSString *key in constraints) {
     NSAssert([key isKindOfClass:[NSString class]],
diff --git a/webrtc/api/objc/RTCMediaStream.h b/webrtc/api/objc/RTCMediaStream.h
index 7df1ea8..e3ab754 100644
--- a/webrtc/api/objc/RTCMediaStream.h
+++ b/webrtc/api/objc/RTCMediaStream.h
@@ -11,7 +11,6 @@
 #import <Foundation/Foundation.h>
 
 NS_ASSUME_NONNULL_BEGIN
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
 
 @class RTCAudioTrack;
 @class RTCPeerConnectionFactory;
@@ -20,12 +19,10 @@
 @interface RTCMediaStream : NSObject
 
 /** The audio tracks in this stream. */
-@property(nonatomic, strong, readonly) NSArray *audioTracks;
-// @property(nonatomic, strong, readonly) NSArray<RTCAudioTrack *> *audioTracks;
+@property(nonatomic, strong, readonly) NSArray<RTCAudioTrack *> *audioTracks;
 
 /** The video tracks in this stream. */
-@property(nonatomic, strong, readonly) NSArray *videoTracks;
-// @property(nonatomic, strong, readonly) NSArray<RTCVideoTrack *> *videoTracks;
+@property(nonatomic, strong, readonly) NSArray<RTCVideoTrack *> *videoTracks;
 
 /** An identifier for this media stream. */
 @property(nonatomic, readonly) NSString *streamId;
diff --git a/webrtc/api/objc/RTCMediaStream.mm b/webrtc/api/objc/RTCMediaStream.mm
index 3c3e4d9..6660223 100644
--- a/webrtc/api/objc/RTCMediaStream.mm
+++ b/webrtc/api/objc/RTCMediaStream.mm
@@ -19,8 +19,6 @@
 #import "webrtc/api/objc/RTCVideoTrack+Private.h"
 #import "webrtc/base/objc/NSString+StdString.h"
 
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
-
 @implementation RTCMediaStream {
   NSMutableArray *_audioTracks;
   NSMutableArray *_videoTracks;
@@ -37,13 +35,11 @@
   return [self initWithNativeMediaStream:stream];
 }
 
-- (NSArray *)audioTracks {
-// - (NSArray<RTCAudioTrack *> *)audioTracks {
+- (NSArray<RTCAudioTrack *> *)audioTracks {
   return [_audioTracks copy];
 }
 
-- (NSArray *)videoTracks {
-// - (NSArray<RTCVideoTrack *> *)videoTracks {
+- (NSArray<RTCVideoTrack *> *)videoTracks {
   return [_videoTracks copy];
 }
 
diff --git a/webrtc/api/objc/RTCPeerConnection+Stats.mm b/webrtc/api/objc/RTCPeerConnection+Stats.mm
index 6a506d4..5032c84 100644
--- a/webrtc/api/objc/RTCPeerConnection+Stats.mm
+++ b/webrtc/api/objc/RTCPeerConnection+Stats.mm
@@ -16,15 +16,12 @@
 #import "webrtc/api/objc/RTCStatsReport+Private.h"
 #import "webrtc/base/objc/NSString+StdString.h"
 
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
-
 namespace webrtc {
 
 class StatsObserverAdapter : public StatsObserver {
  public:
   StatsObserverAdapter(void (^completionHandler)
-      (NSArray *stats)) {
-      // (NSArray<RTCStatsReport *> *stats)) {
+      (NSArray<RTCStatsReport *> *stats)) {
     completion_handler_ = completionHandler;
   }
 
@@ -45,8 +42,7 @@
   }
 
  private:
-  void (^completion_handler_)(NSArray *stats);
-  // void (^completion_handler_)(NSArray<RTCStatsReport *> *stats);
+  void (^completion_handler_)(NSArray<RTCStatsReport *> *stats);
 };
 }  // namespace webrtc
 
@@ -55,8 +51,7 @@
 - (void)statsForTrack:(RTCMediaStreamTrack *)mediaStreamTrack
      statsOutputLevel:(RTCStatsOutputLevel)statsOutputLevel
     completionHandler:
-    (void (^)(NSArray *stats))completionHandler {
-    // (void (^)(NSArray<RTCStatsReport *> *stats))completionHandler {
+    (void (^)(NSArray<RTCStatsReport *> *stats))completionHandler {
   rtc::scoped_refptr<webrtc::StatsObserverAdapter> observer(
       new rtc::RefCountedObject<webrtc::StatsObserverAdapter>
           (completionHandler));
diff --git a/webrtc/api/objc/RTCPeerConnection.h b/webrtc/api/objc/RTCPeerConnection.h
index 72645b5..80e8bf3 100644
--- a/webrtc/api/objc/RTCPeerConnection.h
+++ b/webrtc/api/objc/RTCPeerConnection.h
@@ -22,9 +22,8 @@
 @class RTCStatsReport;
 
 NS_ASSUME_NONNULL_BEGIN
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
 
-extern NSString * _Nonnull const kRTCPeerConnectionErrorDomain;
+extern NSString * const kRTCPeerConnectionErrorDomain;
 extern int const kRTCSessionDescriptionErrorCode;
 
 /** Represents the signaling state of the peer connection. */
@@ -67,36 +66,35 @@
 @protocol RTCPeerConnectionDelegate <NSObject>
 
 /** Called when the SignalingState changed. */
-- (void)peerConnection:(nonnull RTCPeerConnection *)peerConnection
+- (void)peerConnection:(RTCPeerConnection *)peerConnection
     didChangeSignalingState:(RTCSignalingState)stateChanged;
 
 /** Called when media is received on a new stream from remote peer. */
-- (void)peerConnection:(nonnull RTCPeerConnection *)peerConnection
-          didAddStream:(nonnull RTCMediaStream *)stream;
+- (void)peerConnection:(RTCPeerConnection *)peerConnection
+          didAddStream:(RTCMediaStream *)stream;
 
 /** Called when a remote peer closes a stream. */
-- (void)peerConnection:(nonnull RTCPeerConnection *)peerConnection
-       didRemoveStream:(nonnull RTCMediaStream *)stream;
+- (void)peerConnection:(RTCPeerConnection *)peerConnection
+       didRemoveStream:(RTCMediaStream *)stream;
 
 /** Called when negotiation is needed, for example ICE has restarted. */
-- (void)peerConnectionShouldNegotiate:
-    (nonnull RTCPeerConnection *)peerConnection;
+- (void)peerConnectionShouldNegotiate:(RTCPeerConnection *)peerConnection;
 
 /** Called any time the IceConnectionState changes. */
-- (void)peerConnection:(nonnull RTCPeerConnection *)peerConnection
+- (void)peerConnection:(RTCPeerConnection *)peerConnection
     didChangeIceConnectionState:(RTCIceConnectionState)newState;
 
 /** Called any time the IceGatheringState changes. */
-- (void)peerConnection:(nonnull RTCPeerConnection *)peerConnection
+- (void)peerConnection:(RTCPeerConnection *)peerConnection
     didChangeIceGatheringState:(RTCIceGatheringState)newState;
 
 /** New ice candidate has been found. */
-- (void)peerConnection:(nonnull RTCPeerConnection *)peerConnection
-    didGenerateIceCandidate:(nonnull RTCIceCandidate *)candidate;
+- (void)peerConnection:(RTCPeerConnection *)peerConnection
+    didGenerateIceCandidate:(RTCIceCandidate *)candidate;
 
 /** New data channel has been opened. */
-- (void)peerConnection:(nonnull RTCPeerConnection *)peerConnection
-    didOpenDataChannel:(nonnull RTCDataChannel *)dataChannel;
+- (void)peerConnection:(RTCPeerConnection *)peerConnection
+    didOpenDataChannel:(RTCDataChannel *)dataChannel;
 
 @end
 
@@ -107,7 +105,7 @@
  *  streams being added or removed.
  */
 @property(nonatomic, weak, nullable) id<RTCPeerConnectionDelegate> delegate;
-@property(nonatomic, readonly, nonnull) NSArray *localStreams;
+@property(nonatomic, readonly) NSArray *localStreams;
 @property(nonatomic, readonly, nullable)
     RTCSessionDescription *localDescription;
 @property(nonatomic, readonly, nullable)
@@ -116,18 +114,18 @@
 @property(nonatomic, readonly) RTCIceConnectionState iceConnectionState;
 @property(nonatomic, readonly) RTCIceGatheringState iceGatheringState;
 
-- (nonnull instancetype)init NS_UNAVAILABLE;
+- (instancetype)init NS_UNAVAILABLE;
 
 /** Initialize an RTCPeerConnection with a configuration, constraints, and
  *  delegate.
  */
-- (nonnull instancetype)initWithFactory:
-    (nonnull RTCPeerConnectionFactory *)factory
-                          configuration:
-    (nonnull RTCConfiguration *)configuration
-                            constraints:
-    (nonnull RTCMediaConstraints *)constraints
-                               delegate:
+- (instancetype)initWithFactory:
+    (RTCPeerConnectionFactory *)factory
+                  configuration:
+    (RTCConfiguration *)configuration
+                    constraints:
+    (RTCMediaConstraints *)constraints
+                       delegate:
     (nullable id<RTCPeerConnectionDelegate>)delegate
     NS_DESIGNATED_INITIALIZER;
 
@@ -135,33 +133,33 @@
 - (void)close;
 
 /** Provide a remote candidate to the ICE Agent. */
-- (void)addIceCandidate:(nonnull RTCIceCandidate *)candidate;
+- (void)addIceCandidate:(RTCIceCandidate *)candidate;
 
 /** Add a new media stream to be sent on this peer connection. */
-- (void)addStream:(nonnull RTCMediaStream *)stream;
+- (void)addStream:(RTCMediaStream *)stream;
 
 /** Remove the given media stream from this peer connection. */
-- (void)removeStream:(nonnull RTCMediaStream *)stream;
+- (void)removeStream:(RTCMediaStream *)stream;
 
 /** Generate an SDP offer. */
-- (void)offerForConstraints:(nonnull RTCMediaConstraints *)constraints
+- (void)offerForConstraints:(RTCMediaConstraints *)constraints
           completionHandler:(nullable void (^)
     (RTCSessionDescription * _Nullable sdp,
      NSError * _Nullable error))completionHandler;
 
 /** Generate an SDP answer. */
-- (void)answerForConstraints:(nonnull RTCMediaConstraints *)constraints
+- (void)answerForConstraints:(RTCMediaConstraints *)constraints
            completionHandler:(nullable void (^)
     (RTCSessionDescription * _Nullable sdp,
      NSError * _Nullable error))completionHandler;
 
 /** Apply the supplied RTCSessionDescription as the local description. */
-- (void)setLocalDescription:(nonnull RTCSessionDescription *)sdp
+- (void)setLocalDescription:(RTCSessionDescription *)sdp
           completionHandler:
     (nullable void (^)(NSError * _Nullable error))completionHandler;
 
 /** Apply the supplied RTCSessionDescription as the remote description. */
-- (void)setRemoteDescription:(nonnull RTCSessionDescription *)sdp
+- (void)setRemoteDescription:(RTCSessionDescription *)sdp
            completionHandler:
     (nullable void (^)(NSError * _Nullable error))completionHandler;
 
@@ -170,8 +168,8 @@
 @interface RTCPeerConnection (DataChannel)
 
 /** Create a new data channel with the given label and configuration. */
-- (nonnull RTCDataChannel *)dataChannelForLabel:(nonnull NSString *)label
-    configuration:(nonnull RTCDataChannelConfiguration *)configuration;
+- (RTCDataChannel *)dataChannelForLabel:(NSString *)label
+    configuration:(RTCDataChannelConfiguration *)configuration;
 
 @end
 
@@ -184,8 +182,7 @@
     (nullable RTCMediaStreamTrack *)mediaStreamTrack
      statsOutputLevel:(RTCStatsOutputLevel)statsOutputLevel
     completionHandler:
-    (nullable void (^)(NSArray * _Nonnull stats))completionHandler;
-    // (nullable void (^)(NSArray<RTCStatsReport *> *stats))completionHandler;
+    (nullable void (^)(NSArray<RTCStatsReport *> *stats))completionHandler;
 
 @end
 
diff --git a/webrtc/api/objc/RTCStatsReport.h b/webrtc/api/objc/RTCStatsReport.h
index 9a120b9..fc66faf 100644
--- a/webrtc/api/objc/RTCStatsReport.h
+++ b/webrtc/api/objc/RTCStatsReport.h
@@ -11,7 +11,6 @@
 #import <Foundation/Foundation.h>
 
 NS_ASSUME_NONNULL_BEGIN
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
 
 /** This does not currently conform to the spec. */
 @interface RTCStatsReport : NSObject
@@ -26,8 +25,7 @@
 @property(nonatomic, readonly) NSString *statsId;
 
 /** A dictionary holding the actual stats. */
-@property(nonatomic, readonly) NSDictionary *values;
-// @property(nonatomic, readonly) NSDictionary<NSString *, NSString *> *values;
+@property(nonatomic, readonly) NSDictionary<NSString *, NSString *> *values;
 
 - (instancetype)init NS_UNAVAILABLE;
 
diff --git a/webrtc/api/objc/RTCStatsReport.mm b/webrtc/api/objc/RTCStatsReport.mm
index 76de950..b3cd1a1 100644
--- a/webrtc/api/objc/RTCStatsReport.mm
+++ b/webrtc/api/objc/RTCStatsReport.mm
@@ -16,8 +16,6 @@
 #import "webrtc/base/objc/NSString+StdString.h"
 #import "webrtc/base/objc/RTCLogging.h"
 
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
-
 @implementation RTCStatsReport
 
 @synthesize timestamp = _timestamp;
diff --git a/webrtc/api/objc/RTCVideoFrame.h b/webrtc/api/objc/RTCVideoFrame.h
index c710290..8ed23ba 100644
--- a/webrtc/api/objc/RTCVideoFrame.h
+++ b/webrtc/api/objc/RTCVideoFrame.h
@@ -11,7 +11,6 @@
 #import <Foundation/Foundation.h>
 
 NS_ASSUME_NONNULL_BEGIN
-// TODO(hjon): Update nullability types. See http://crbug/webrtc/5592
 
 @interface RTCVideoFrame : NSObject
 
@@ -31,7 +30,7 @@
 @property(nonatomic, readonly) int32_t uPitch;
 @property(nonatomic, readonly) int32_t vPitch;
 
-- (nonnull instancetype)init NS_UNAVAILABLE;
+- (instancetype)init NS_UNAVAILABLE;
 
 @end