Revert "Disallows reusing RTCIceTransport."

This reverts commit 1aaab3f0.

Reason for revert: Suspected of causing WebKit LayoutTests failures on 10.11, compare https://ci.chromium.org/p/chromium/builders/ci/Mac10.11%20Tests/37268 FindIt points out this CL.


Original change's description:
> Disallows reusing RTCIceTransport.
> 
> Currently if an RTCIceTransport that comes from an RTCPeerConnection is
> reused to create and RTCQuicTransport there is a crash. This disallows
> this from happening by throwing an exception if the client attempts to
> do this.
> 
> Bug: 10589
> Change-Id: Idcf538972516825fef3b275d062a19d0bd7a68c5
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1593872
> Commit-Queue: Seth Hampson <shampson@chromium.org>
> Reviewed-by: Steve Anton <steveanton@chromium.org>
> Auto-Submit: Seth Hampson <shampson@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#656241}

TBR=shampson@chromium.org,steveanton@chromium.org,amithi@chromium.org

Change-Id: I7eca98de36593304f7fbedeb9cfa2b12dc276254
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 10589
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1593379Reviewed-by: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Cr-Commit-Position: refs/heads/master@{#656325}

third_party/blink/renderer/modules/peerconnection/rtc_ice_transport.cc

@@ -194,15 +194,10 @@ bool RTCIceTransport::HasConsumer() const {
   return consumer_;
 }
 
-bool RTCIceTransport::IsFromPeerConnection() const {
-  return peer_connection_;
-}
-
 IceTransportProxy* RTCIceTransport::ConnectConsumer(
     RTCQuicTransport* consumer) {
   DCHECK(consumer);
   DCHECK(proxy_);
-  DCHECK(!peer_connection_);
   if (!consumer_) {
     consumer_ = consumer;
   } else {

third_party/blink/renderer/modules/peerconnection/rtc_ice_transport.h

@@ -102,21 +102,6 @@ class MODULES_EXPORT RTCIceTransport final
   // a QuicTransportProxy. It may be called repeatedly with the same
   // RTCQuicTransport.
   bool HasConsumer() const;
-  // If |this| was created from an RTCPeerConnection.
-  //
-  // Background: This is because we don't reuse an RTCIceTransport that has been
-  // created from an RTCPeerConnection for an RTCQuicTransport (see
-  // bugs.webrtc.org/10591). The core issue here is that the source of truth for
-  // connecting a consumer to ICE is at the P2PTransportChannel. In the case of
-  // RTCPeerConnection, the P2PTransportChannel is already connected and given
-  // to the RTCIceTransport. In the case of the RTCQuicTransport it uses the
-  // RTCIceTransport as the source of truth for enforcing just one connected
-  // consumer. Possible fixes to this issue could include: -Use the
-  // P2PTransportChannel as the source of truth directly (calling this
-  // synchronously from the main thread)
-  // -Asynchronously connect to the P2PTransport - if the count of connected
-  // transports to the P2PTransportChannel is > 1, then throw an exception.
-  bool IsFromPeerConnection() const;
   IceTransportProxy* ConnectConsumer(RTCQuicTransport* consumer);
   void DisconnectConsumer(RTCQuicTransport* consumer);
 

third_party/blink/renderer/modules/peerconnection/rtc_quic_transport.cc

@@ -115,14 +115,6 @@ RTCQuicTransport* RTCQuicTransport::Create(
                                       "has a connected RTCQuicTransport.");
     return nullptr;
   }
-  if (transport->IsFromPeerConnection()) {
-    exception_state.ThrowDOMException(
-        DOMExceptionCode::kInvalidStateError,
-        "Cannot construct an RTCQuicTransport "
-        "with an RTCIceTransport that came from an "
-        "RTCPeerConnection.");
-    return nullptr;
-  }
   for (const auto& certificate : certificates) {
     if (certificate->expires() < ConvertSecondsToDOMTimeStamp(CurrentTime())) {
       exception_state.ThrowTypeError(

third_party/blink/web_tests/external/wpt/webrtc-quic/RTCQuicTransport.https.html

@@ -4,7 +4,6 @@
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <script src="../webrtc/RTCIceTransport-extension-helper.js"></script>
-<script src="../webrtc/RTCPeerConnection-helper.js"></script>
 <script src="RTCQuicTransport-helper.js"></script>
 <script src="../webrtc/dictionary-helper.js"></script>
 <script>
@@ -49,23 +48,6 @@ test(t => {
 }, 'RTCQuicTransport constructor throws if passed an RTCIceTransport that ' +
     'already has an active RTCQuicTransport.');
 
-promise_test(async t => {
-  const pc1 = new RTCPeerConnection();
-  t.add_cleanup(() => pc1.close());
-  const pc2 = new RTCPeerConnection();
-  t.add_cleanup(() => pc2.close());
-
-  pc1.createDataChannel('test');
-  await doSignalingHandshake(pc1, pc2);
-  exchangeIceCandidates(pc1, pc2);
-  await listenToIceConnected(pc1);
-  const iceTransport = pc1.sctp.transport.iceTransport;
-
-  assert_throws('InvalidStateError',
-      () => makeQuicTransport(t, iceTransport));
-}, 'RTCQuicTransport constructor throws if passed an RTCIceTransport that ' +
-    'came from an RTCPeerConnection.');
-
 test(t => {
   const quicTransport = makeStandaloneQuicTransport(t);
   quicTransport.stop();