Add flag in ios to support disabling high-cost networks.

This depends on CL:
https://codereview.webrtc.org/1987833002/

BUG=
R=tkchin@webrtc.org

Review URL: https://codereview.webrtc.org/2030443002 .

Cr-Commit-Position: refs/heads/master@{#13046}

webrtc/sdk/objc/Framework/Classes/RTCConfiguration+Private.h

@@ -48,6 +48,14 @@ NS_ASSUME_NONNULL_BEGIN
 
 + (NSString *)stringForTcpCandidatePolicy:(RTCTcpCandidatePolicy)policy;
 
++ (webrtc::PeerConnectionInterface::CandidateNetworkPolicy)
+    nativeCandidateNetworkPolicyForPolicy:(RTCCandidateNetworkPolicy)policy;
+
++ (RTCCandidateNetworkPolicy)candidateNetworkPolicyForNativePolicy:
+    (webrtc::PeerConnectionInterface::CandidateNetworkPolicy)nativePolicy;
+
++ (NSString *)stringForCandidateNetworkPolicy:(RTCCandidateNetworkPolicy)policy;
+
 /**
  * RTCConfiguration struct representation of this RTCConfiguration. This is
  * needed to pass to the underlying C++ APIs.

webrtc/sdk/objc/Framework/Classes/RTCConfiguration.mm

@@ -25,6 +25,7 @@
 @synthesize bundlePolicy = _bundlePolicy;
 @synthesize rtcpMuxPolicy = _rtcpMuxPolicy;
 @synthesize tcpCandidatePolicy = _tcpCandidatePolicy;
+@synthesize candidateNetworkPolicy = _candidateNetworkPolicy;
 @synthesize continualGatheringPolicy = _continualGatheringPolicy;
 @synthesize audioJitterBufferMaxPackets = _audioJitterBufferMaxPackets;
 @synthesize iceConnectionReceivingTimeout = _iceConnectionReceivingTimeout;
@@ -46,6 +47,8 @@
         [[self class] rtcpMuxPolicyForNativePolicy:config.rtcp_mux_policy];
     _tcpCandidatePolicy = [[self class] tcpCandidatePolicyForNativePolicy:
         config.tcp_candidate_policy];
+    _candidateNetworkPolicy = [[self class]
+        candidateNetworkPolicyForNativePolicy:config.candidate_network_policy];
     webrtc::PeerConnectionInterface::ContinualGatheringPolicy nativePolicy =
         config.continual_gathering_policy;
     _continualGatheringPolicy =
@@ -62,12 +65,13 @@
 
 - (NSString *)description {
   return [NSString stringWithFormat:
-      @"RTCConfiguration: {\n%@\n%@\n%@\n%@\n%@\n%@\n%d\n%d\n%d\n%d\n}\n",
+      @"RTCConfiguration: {\n%@\n%@\n%@\n%@\n%@\n%@\n%@\n%d\n%d\n%d\n%d\n}\n",
       _iceServers,
       [[self class] stringForTransportPolicy:_iceTransportPolicy],
       [[self class] stringForBundlePolicy:_bundlePolicy],
       [[self class] stringForRtcpMuxPolicy:_rtcpMuxPolicy],
       [[self class] stringForTcpCandidatePolicy:_tcpCandidatePolicy],
+      [[self class] stringForCandidateNetworkPolicy:_candidateNetworkPolicy],
       [[self class]
           stringForContinualGatheringPolicy:_continualGatheringPolicy],
       _audioJitterBufferMaxPackets,
@@ -94,6 +98,8 @@
       [[self class] nativeRtcpMuxPolicyForPolicy:_rtcpMuxPolicy];
   nativeConfig->tcp_candidate_policy =
       [[self class] nativeTcpCandidatePolicyForPolicy:_tcpCandidatePolicy];
+  nativeConfig->candidate_network_policy = [[self class]
+      nativeCandidateNetworkPolicyForPolicy:_candidateNetworkPolicy];
   nativeConfig->continual_gathering_policy = [[self class]
       nativeContinualGatheringPolicyForPolicy:_continualGatheringPolicy];
   nativeConfig->audio_jitter_buffer_max_packets = _audioJitterBufferMaxPackets;
@@ -234,6 +240,16 @@
   }
 }
 
++ (webrtc::PeerConnectionInterface::CandidateNetworkPolicy)
+    nativeCandidateNetworkPolicyForPolicy:(RTCCandidateNetworkPolicy)policy {
+  switch (policy) {
+    case RTCCandidateNetworkPolicyAll:
+      return webrtc::PeerConnectionInterface::kCandidateNetworkPolicyAll;
+    case RTCCandidateNetworkPolicyLowCost:
+      return webrtc::PeerConnectionInterface::kCandidateNetworkPolicyLowCost;
+  }
+}
+
 + (rtc::KeyType)nativeEncryptionKeyTypeForKeyType:
     (RTCEncryptionKeyType)keyType {
   switch (keyType) {
@@ -263,6 +279,26 @@
   }
 }
 
++ (RTCCandidateNetworkPolicy)candidateNetworkPolicyForNativePolicy:
+    (webrtc::PeerConnectionInterface::CandidateNetworkPolicy)nativePolicy {
+  switch (nativePolicy) {
+    case webrtc::PeerConnectionInterface::kCandidateNetworkPolicyAll:
+      return RTCCandidateNetworkPolicyAll;
+    case webrtc::PeerConnectionInterface::kCandidateNetworkPolicyLowCost:
+      return RTCCandidateNetworkPolicyLowCost;
+  }
+}
+
++ (NSString *)stringForCandidateNetworkPolicy:
+    (RTCCandidateNetworkPolicy)policy {
+  switch (policy) {
+    case RTCCandidateNetworkPolicyAll:
+      return @"CANDIDATE_ALL_NETWORKS";
+    case RTCCandidateNetworkPolicyLowCost:
+      return @"CANDIDATE_LOW_COST_NETWORKS";
+  }
+}
+
 + (webrtc::PeerConnectionInterface::ContinualGatheringPolicy)
     nativeContinualGatheringPolicyForPolicy:
         (RTCContinualGatheringPolicy)policy {

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCConfiguration.h

@@ -44,6 +44,12 @@ typedef NS_ENUM(NSInteger, RTCTcpCandidatePolicy) {
   RTCTcpCandidatePolicyDisabled
 };
 
+/** Represents the candidate network policy. */
+typedef NS_ENUM(NSInteger, RTCCandidateNetworkPolicy) {
+  RTCCandidateNetworkPolicyAll,
+  RTCCandidateNetworkPolicyLowCost
+};
+
 /** Represents the continual gathering policy. */
 typedef NS_ENUM(NSInteger, RTCContinualGatheringPolicy) {
   RTCContinualGatheringPolicyGatherOnce,
@@ -74,6 +80,7 @@ RTC_EXPORT
 /** The rtcp-mux policy to use when gathering ICE candidates. */
 @property(nonatomic, assign) RTCRtcpMuxPolicy rtcpMuxPolicy;
 @property(nonatomic, assign) RTCTcpCandidatePolicy tcpCandidatePolicy;
+@property(nonatomic, assign) RTCCandidateNetworkPolicy candidateNetworkPolicy;
 @property(nonatomic, assign)
     RTCContinualGatheringPolicy continualGatheringPolicy;
 @property(nonatomic, assign) int audioJitterBufferMaxPackets;

webrtc/sdk/objc/Framework/UnitTests/RTCConfigurationTest.mm

@@ -35,6 +35,7 @@
   config.bundlePolicy = RTCBundlePolicyMaxBundle;
   config.rtcpMuxPolicy = RTCRtcpMuxPolicyNegotiate;
   config.tcpCandidatePolicy = RTCTcpCandidatePolicyDisabled;
+  config.candidateNetworkPolicy = RTCCandidateNetworkPolicyLowCost;
   const int maxPackets = 60;
   const int timeout = 1;
   const int interval = 2;
@@ -60,6 +61,8 @@
             nativeConfig->rtcp_mux_policy);
   EXPECT_EQ(webrtc::PeerConnectionInterface::kTcpCandidatePolicyDisabled,
             nativeConfig->tcp_candidate_policy);
+  EXPECT_EQ(webrtc::PeerConnectionInterface::kCandidateNetworkPolicyLowCost,
+            nativeConfig->candidate_network_policy);
   EXPECT_EQ(maxPackets, nativeConfig->audio_jitter_buffer_max_packets);
   EXPECT_EQ(timeout, nativeConfig->ice_connection_receiving_timeout);
   EXPECT_EQ(interval, nativeConfig->ice_backup_candidate_pair_ping_interval);