Reland of GN: Enable ARC for Mac and iOS in rtc_* templates

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

 /*
  *  Copyright 2015 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.
  */
 
@@ skipping 35 matching lines @@
   config.audioJitterBufferFastAccelerate = YES;
   config.iceConnectionReceivingTimeout = timeout;
   config.iceBackupCandidatePairPingInterval = interval;
   config.continualGatheringPolicy =
       RTCContinualGatheringPolicyGatherContinually;
   config.shouldPruneTurnPorts = YES;
 
   RTCMediaConstraints *contraints = [[RTCMediaConstraints alloc] initWithMandatoryConstraints:@{}
       optionalConstraints:nil];
   RTCPeerConnectionFactory *factory = [[RTCPeerConnectionFactory alloc] init];
-  RTCPeerConnection *peerConnection = [factory peerConnectionWithConfiguration:config
-      constraints:contraints delegate:nil];
 
-  RTCConfiguration *newConfig = peerConnection.configuration;
-
+  RTCConfiguration *newConfig;
+  @autoreleasepool {
+    RTCPeerConnection *peerConnection =
+        [factory peerConnectionWithConfiguration:config constraints:contraints delegate:nil];
+    newConfig = peerConnection.configuration;
+  }
   EXPECT_EQ([config.iceServers count], [newConfig.iceServers count]);
   RTCIceServer *newServer = newConfig.iceServers[0];
   RTCIceServer *origServer = config.iceServers[0];
   std::string origUrl = origServer.urlStrings.firstObject.UTF8String;
   std::string url = newServer.urlStrings.firstObject.UTF8String;
   EXPECT_EQ(origUrl, url);
 
   EXPECT_EQ(config.iceTransportPolicy, newConfig.iceTransportPolicy);
   EXPECT_EQ(config.bundlePolicy, newConfig.bundlePolicy);
   EXPECT_EQ(config.rtcpMuxPolicy, newConfig.rtcpMuxPolicy);
@@ skipping 11 matching lines @@
 @end
 
 TEST(RTCPeerConnectionTest, ConfigurationGetterTest) {
   @autoreleasepool {
     RTCPeerConnectionTest *test = [[RTCPeerConnectionTest alloc] init];
     [test testConfigurationGetter];
   }
 }