Implement RTCPeerConnection.canTrickleIceCandidates

This is a read-only attribute revealing a detail from the
SDP offer/answer exchange.

Spec:
https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-cantrickleicecandidates

Bug: chromium:708484
Change-Id: I8fab2050bac0237cb513d70c8c257a54bdc0a4b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2082512Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Commit-Queue: Harald Alvestrand <hta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#746378}

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

@@ -1967,6 +1967,25 @@ String RTCPeerConnection::connectionState() const {
   return String();
 }
 
+bool RTCPeerConnection::canTrickleIceCandidates(bool& is_null) const {
+  is_null = true;
+  if (closed_ || !peer_handler_->RemoteDescription()) {
+    return false;
+  }
+  webrtc::PeerConnectionInterface* native_connection =
+      peer_handler_->NativePeerConnection();
+  if (!native_connection) {
+    return false;
+  }
+  absl::optional<bool> can_trickle =
+      native_connection->can_trickle_ice_candidates();
+  if (!can_trickle) {
+    return false;
+  }
+  is_null = false;
+  return *can_trickle;
+}
+
 void RTCPeerConnection::restartIce() {
   if (closed_)
     return;

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

@@ -227,6 +227,8 @@ class MODULES_EXPORT RTCPeerConnection final
 
   String connectionState() const;
 
+  bool canTrickleIceCandidates(bool&) const;
+
   void restartIce();
 
   // A local stream is any stream associated with a sender.

third_party/blink/renderer/modules/peerconnection/rtc_peer_connection.idl

@@ -83,7 +83,7 @@ enum RTCPeerConnectionState {
     readonly attribute RTCIceGatheringState iceGatheringState;
     readonly attribute RTCIceConnectionState iceConnectionState;
     readonly attribute RTCPeerConnectionState connectionState;
-    // readonly attribute boolean? canTrickleIceCandidates;
+    readonly attribute boolean? canTrickleIceCandidates;
     void restartIce();
     [CallWith=ScriptState] RTCConfiguration getConfiguration();
     [CallWith=ScriptState, RaisesException] void setConfiguration(RTCConfiguration configuration);

third_party/blink/web_tests/external/wpt/webrtc/RTCPeerConnection-canTrickleIceCandidates-expected.txt

-This is a testharness.js-based test.
-FAIL canTrickleIceCandidates property is null prior to setRemoteDescription assert_equals: canTrickleIceCandidates property is null expected (object) null but got (undefined) undefined
-FAIL canTrickleIceCandidates property is true after setRemoteDescription with a=ice-options:trickle assert_true: canTrickleIceCandidates property is true after setRemoteDescription expected true got undefined
-FAIL canTrickleIceCandidates property is false after setRemoteDescription without a=ice-options:trickle assert_false: canTrickleIceCandidates property is false after setRemoteDescription expected false got undefined
-Harness: the test ran to completion.
-

third_party/blink/web_tests/external/wpt/webrtc/RTCPeerConnection-constructor-expected.txt

-This is a testharness.js-based test.
-PASS RTCPeerConnection.length
-PASS new RTCPeerConnection()
-PASS new RTCPeerConnection(null)
-PASS new RTCPeerConnection(undefined)
-PASS new RTCPeerConnection({})
-PASS new RTCPeerConnection({ certificates: null })
-PASS new RTCPeerConnection({ certificates: undefined })
-PASS new RTCPeerConnection({ certificates: [] })
-PASS new RTCPeerConnection({ certificates: [null] })
-PASS new RTCPeerConnection({ certificates: [undefined] })
-PASS new RTCPeerConnection({ iceCandidatePoolSize: toNumberThrows })
-PASS localDescription initial value
-PASS currentLocalDescription initial value
-PASS pendingLocalDescription initial value
-PASS remoteDescription initial value
-PASS currentRemoteDescription initial value
-PASS pendingRemoteDescription initial value
-PASS signalingState initial value
-PASS iceGatheringState initial value
-PASS iceConnectionState initial value
-PASS connectionState initial value
-FAIL canTrickleIceCandidates initial value assert_equals: expected (object) null but got (undefined) undefined
-Harness: the test ran to completion.
-

third_party/blink/web_tests/external/wpt/webrtc/idlharness.https.window-expected.txt

 This is a testharness.js-based test.
-Found 496 tests; 472 PASS, 24 FAIL, 0 TIMEOUT, 0 NOTRUN.
+Found 496 tests; 474 PASS, 22 FAIL, 0 TIMEOUT, 0 NOTRUN.
 PASS idl_test setup
 PASS idl_test validation
 PASS Test driver for asyncInitCertificate
@@ -38,7 +38,7 @@ PASS RTCPeerConnection interface: attribute signalingState
 PASS RTCPeerConnection interface: attribute iceGatheringState
 PASS RTCPeerConnection interface: attribute iceConnectionState
 PASS RTCPeerConnection interface: attribute connectionState
-FAIL RTCPeerConnection interface: attribute canTrickleIceCandidates assert_true: The prototype object must have a property "canTrickleIceCandidates" expected true got false
+PASS RTCPeerConnection interface: attribute canTrickleIceCandidates
 PASS RTCPeerConnection interface: operation restartIce()
 PASS RTCPeerConnection interface: operation getConfiguration()
 FAIL RTCPeerConnection interface: operation setConfiguration(optional RTCConfiguration) assert_equals: property has wrong .length expected 0 but got 1
@@ -89,7 +89,7 @@ PASS RTCPeerConnection interface: new RTCPeerConnection() must inherit property
 PASS RTCPeerConnection interface: new RTCPeerConnection() must inherit property "iceGatheringState" with the proper type
 PASS RTCPeerConnection interface: new RTCPeerConnection() must inherit property "iceConnectionState" with the proper type
 PASS RTCPeerConnection interface: new RTCPeerConnection() must inherit property "connectionState" with the proper type
-FAIL RTCPeerConnection interface: new RTCPeerConnection() must inherit property "canTrickleIceCandidates" with the proper type assert_inherits: property "canTrickleIceCandidates" not found in prototype chain
+PASS RTCPeerConnection interface: new RTCPeerConnection() must inherit property "canTrickleIceCandidates" with the proper type
 PASS RTCPeerConnection interface: new RTCPeerConnection() must inherit property "restartIce()" with the proper type
 PASS RTCPeerConnection interface: new RTCPeerConnection() must inherit property "getConfiguration()" with the proper type
 PASS RTCPeerConnection interface: new RTCPeerConnection() must inherit property "setConfiguration(optional RTCConfiguration)" with the proper type

third_party/blink/web_tests/virtual/stable/webexposed/global-interface-listing-expected.txt

@@ -5346,6 +5346,7 @@ interface RTCIceTransport : EventTarget
 interface RTCPeerConnection : EventTarget
     static method generateCertificate
     attribute @@toStringTag
+    getter canTrickleIceCandidates
     getter connectionState
     getter currentLocalDescription
     getter currentRemoteDescription
@@ -9182,6 +9183,7 @@ interface webkitMediaStream : EventTarget
 interface webkitRTCPeerConnection : EventTarget
     static method generateCertificate
     attribute @@toStringTag
+    getter canTrickleIceCandidates
     getter connectionState
     getter currentLocalDescription
     getter currentRemoteDescription

third_party/blink/web_tests/webexposed/global-interface-listing-expected.txt

@@ -6336,6 +6336,7 @@ interface RTCIceTransport : EventTarget
 interface RTCPeerConnection : EventTarget
     static method generateCertificate
     attribute @@toStringTag
+    getter canTrickleIceCandidates
     getter connectionState
     getter currentLocalDescription
     getter currentRemoteDescription
@@ -11447,6 +11448,7 @@ interface webkitMediaStream : EventTarget
 interface webkitRTCPeerConnection : EventTarget
     static method generateCertificate
     attribute @@toStringTag
+    getter canTrickleIceCandidates
     getter connectionState
     getter currentLocalDescription
     getter currentRemoteDescription