Revert "Remove the enabling of RTP data channels."

This reverts commit c2dd88a3.

Reason for revert: broke Meet on Mac Canary, crbug.com/1168301

Original change's description:
> Remove the enabling of RTP data channels.
>
> This is the minimum change to prevent the use of RTP datachannels in Chrome,
> designed to be easily rolled back if needed.
>
> Feature link in Chrome dashboard:
> https://chromestatus.com/feature/6485681910054912
>
> Bug: webrtc:6625
> Change-Id: I19c78f703c8e322d8fa21c120c255942cd2bbd3c
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2632953
> Reviewed-by: Henrik Boström <hbos@chromium.org>
> Reviewed-by: Guido Urdaneta <guidou@chromium.org>
> Commit-Queue: Harald Alvestrand <hta@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#844489}

TBR=hta@chromium.org,hbos@chromium.org,guidou@chromium.org,chromium-scoped@luci-project-accounts.iam.gserviceaccount.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: webrtc:6625
Change-Id: I3cea1636b68ee206c5107a1a8d2c55404236028e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2638598Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: Zhenyao Mo <zmo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844999}

content/browser/webrtc/webrtc_data_browsertest.cc

@@ -52,10 +52,31 @@ IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcDataBrowserTest, CanSetupLegacyCall) {
   MakeTypicalPeerConnectionCall("callWithLegacySdp();");
 }
 
+// This test will make a PeerConnection-based call and test an unreliable text
+// dataChannel.
+// TODO(mallinath) - Remove this test after rtp based data channel is disabled.
+IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcDataBrowserTest, CallWithDataOnly) {
+  MakeTypicalPeerConnectionCall("callWithDataOnly();");
+}
+
 IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcDataBrowserTest, CallWithSctpDataOnly) {
   MakeTypicalPeerConnectionCall("callWithSctpDataOnly();");
 }
 
+// This test will make a PeerConnection-based call and test an unreliable text
+// dataChannel and audio and video tracks.
+// TODO(mallinath) - Remove this test after rtp based data channel is disabled.
+// Flaky. crbug.com/986872
+#if defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(OS_WIN)
+#define MAYBE_CallWithDataAndMedia DISABLED_CallWithDataAndMedia
+#else
+#define MAYBE_CallWithDataAndMedia CallWithDataAndMedia
+#endif
+IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcDataBrowserTest,
+                       MAYBE_CallWithDataAndMedia) {
+  MakeTypicalPeerConnectionCall("callWithDataAndMedia();");
+}
+
 #if defined(MEMORY_SANITIZER)
 // Fails under MemorySanitizer: http://crbug.com/405951
 #define MAYBE_CallWithSctpDataAndMedia DISABLED_CallWithSctpDataAndMedia
@@ -67,4 +88,12 @@ IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcDataBrowserTest,
   MakeTypicalPeerConnectionCall("callWithSctpDataAndMedia();");
 }
 
+// This test will make a PeerConnection-based call and test an unreliable text
+// dataChannel and later add an audio and video track.
+// Doesn't work, therefore disabled: https://crbug.com/293252.
+IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcDataBrowserTest,
+                       DISABLED_CallWithDataAndLaterAddMedia) {
+  MakeTypicalPeerConnectionCall("callWithDataAndLaterAddMedia();");
+}
+
 }  // namespace content

content/test/data/media/peerconnection-call-data.html

@@ -36,18 +36,28 @@
       return removeBundle(useExternalSdes(sdp));
     });
     createConnections({
-      'mandatory': {'DtlsSrtpKeyAgreement': false}
+      'mandatory': {'RtpDataChannels': true, 'DtlsSrtpKeyAgreement': false}
     });
+    var hasExchanged = promiseDataChannelExchange({reliable: false});
     navigator.mediaDevices.getUserMedia({audio: true, video: true})
         .then(addStreamToBothConnectionsAndNegotiate)
         .catch(failTest);
 
     Promise.all([
+      hasExchanged,
       detectVideoPlaying('remote-view-1'),
       detectVideoPlaying('remote-view-2')
     ]).then(reportTestSuccess);
   }
 
+  // Test only a data channel.
+  function callWithDataOnly() {
+    createConnections({optional:[{RtpDataChannels: true}]});
+    promiseDataChannelExchange({reliable: false})
+        .then(reportTestSuccess);
+    negotiate();
+  }
+
   function callWithSctpDataOnly() {
     createConnections({optional: [{DtlsSrtpKeyAgreement: true}]});
     promiseSctpDataChannelExchange({reliable: true})
@@ -55,6 +65,21 @@
     negotiate();
   }
 
+  // Test call with audio, video and a data channel.
+  function callWithDataAndMedia() {
+    createConnections({optional:[{RtpDataChannels: true}]});
+    var hasExchanged = promiseDataChannelExchange({reliable: false});
+    navigator.mediaDevices.getUserMedia({audio: true, video: true})
+        .then(addStreamToBothConnectionsAndNegotiate)
+        .catch(failTest);
+
+    Promise.all([
+      hasExchanged,
+      detectVideoPlaying('remote-view-1'),
+      detectVideoPlaying('remote-view-2')
+    ]).then(reportTestSuccess);
+  }
+
   function callWithSctpDataAndMedia() {
     createConnections({optional: [{DtlsSrtpKeyAgreement: true}]});
     var hasExchanged = promiseSctpDataChannelExchange({reliable: true});
@@ -69,6 +94,27 @@
     ]).then(reportTestSuccess);
   }
 
+  // Test call with a data channel and later add audio and video.
+  function callWithDataAndLaterAddMedia() {
+    createConnections({optional:[{RtpDataChannels: true}]});
+    var hasExchanged = promiseDataChannelExchange({reliable: false});
+    negotiate();
+
+    // Set an event handler for when the data channel has been closed.
+    hasExchanged.then(() => {
+      // When the video is flowing the test is done.
+      return navigator.mediaDevices.getUserMedia({audio: true, video: true})
+          .then(addStreamToBothConnectionsAndNegotiate);
+    }).then(() => {
+      return Promise.all([
+        detectVideoPlaying('remote-view-1'),
+        detectVideoPlaying('remote-view-2')
+      ]);
+    })
+    .then(reportTestSuccess)
+    .catch(failTest);
+  }
+
   // This function is used for setting up a test that:
   // 1. Creates a data channel on |gFirstConnection| and sends data to
   //    |gSecondConnection|.

third_party/blink/renderer/modules/mediastream/media_constraints_impl.cc

@@ -112,6 +112,7 @@ const char kIceRestart[] = "IceRestart";
 const char kUseRtpMux[] = "googUseRtpMUX";
 // Below constraints should be used during PeerConnection construction.
 const char kEnableDtlsSrtp[] = "DtlsSrtpKeyAgreement";
+const char kEnableRtpDataChannels[] = "RtpDataChannels";
 // Google-specific constraint keys.
 // TODO(hta): These need to be made standard or deleted. crbug.com/605673
 const char kEnableDscp[] = "googDscp";
@@ -366,6 +367,16 @@ static void ParseOldStyleNames(
                           WebFeature::kRTCConstraintEnableDtlsSrtpFalse);
       }
       result.enable_dtls_srtp.SetExact(ToBoolean(constraint.value_));
+    } else if (constraint.name_.Equals(kEnableRtpDataChannels)) {
+      bool value = ToBoolean(constraint.value_);
+      if (value) {
+        Deprecation::CountDeprecation(
+            context, WebFeature::kRTCConstraintEnableRtpDataChannelsTrue);
+      } else {
+        UseCounter::Count(context,
+                          WebFeature::kRTCConstraintEnableRtpDataChannelsFalse);
+      }
+      result.enable_rtp_data_channels.SetExact(ToBoolean(constraint.value_));
     } else if (constraint.name_.Equals(kEnableDscp)) {
       result.enable_dscp.SetExact(ToBoolean(constraint.value_));
     } else if (constraint.name_.Equals(kEnableIPv6)) {

third_party/blink/web_tests/fast/peerconnection/RTCPeerConnection-dataChannelTypeCollision.html

+<!DOCTYPE html>
+<html>
+<head>
+<title>RTCPeerConnection data channel type collison</title>
+<script src="../../resources/testharness.js"></script>
+<script src="../../resources/testharnessreport.js"></script>
+</head>
+</body>
+<script>
+promise_test(t => {
+  // This test specifically verifies fix to crbug.com/1030628
+  var mediaConstraints = {
+    optional: [{ RtpDataChannels: true }]
+  }
+  var pc = new RTCPeerConnection({}, mediaConstraints)
+  t.add_cleanup(() => pc.close());
+  pc.createDataChannel('')
+
+  var sd = new RTCSessionDescription({
+    type: 'offer',
+    sdp: 'v=0\r\no=- 2512342596970960666 2 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\na=group:BUNDLE data\r\na=msid-semantic: WMS\r\nm=application 9 UDP/DTLS/SCTP webrtc-datachannel\r\nc=IN IP4 0.0.0.0\r\na=ice-ufrag:xwIt\r\na=ice-pwd:WnJ0omUfzZhL3WX63jJH5mU8\r\na=ice-options:trickle\r\na=fingerprint:sha-256 E5:61:EC:E3:D4:04:55:16:E9:47:95:A7:4E:0C:82:10:A2:70:82:4F:59:29:99:B2:66:40:F2:46:86:A6:23:A3\r\na=setup:actpass\r\na=mid:data\r\na=sctp-port:5000\r\na=max-message-size:262144\r\n',
+  })
+  return promise_rejects_dom(t, "InvalidAccessError", pc.setRemoteDescription(sd));
+}, 'Local RTP channel, remote offer of SCTP channel');
+
+promise_test(async t => {
+  var pc = new RTCPeerConnection();
+  t.add_cleanup(() => pc.close());
+  pc.createDataChannel('');
+  offer = await pc.createOffer();
+  assert_regexp_match(offer.sdp, /m=application .* webrtc-datachannel/);
+  assert_equals(offer.sdp.match(/a=rtpmap:\d+ google-data/), null);
+}, 'Asking for default Data Channels generates appropriate offer');
+
+promise_test(async t => {
+  const rtpConstraints = { optional: [{ RtpDataChannels: true}]};
+
+  var pc = new RTCPeerConnection({}, rtpConstraints);
+  t.add_cleanup(() => pc.close());
+  pc.createDataChannel('');
+  offer = await pc.createOffer();
+  assert_equals(offer.sdp.match(/m=application .* webrtc-datachannel/), null);
+  assert_regexp_match(offer.sdp, /a=rtpmap:\d+ google-data/);
+}, 'Asking for RTP Data Channels generates appropriate offer');
+
+</script>
+</body>
+</html>