Revert "Expose can_trickle_ice_candidates on PeerConnection"

This reverts commit c6a65c8866487c6adc0a7bb472d3bad9389501f9.

Reason for revert: Breaks downstream due to missing default

Original change's description:
> Expose can_trickle_ice_candidates on PeerConnection
> 
> Bug: chromium:708484
> Change-Id: I9a40e75066341f0d9f965bd3718bfcb3f0459533
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/169450
> Commit-Queue: Harald Alvestrand <hta@webrtc.org>
> Reviewed-by: Taylor <deadbeef@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#30653}

TBR=deadbeef@webrtc.org,hta@webrtc.org

Change-Id: Iaa5b977c4237715a8a5127cf167cf6512a3f7059
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:708484
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/169540
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30655}

api/BUILD.gn

@@ -1010,7 +1010,6 @@ if (rtc_include_tests) {
     sources = [ "test/compile_all_headers.cc" ]
 
     deps = [
-      ":dummy_peer_connection",
       ":fake_frame_decryptor",
       ":fake_frame_encryptor",
       ":fake_media_transport",

api/peer_connection_interface.h

@@ -1109,10 +1109,6 @@ class RTC_EXPORT PeerConnectionInterface : public rtc::RefCountInterface {
 
   virtual IceGatheringState ice_gathering_state() = 0;
 
-  // Returns the current state of canTrickleIceCandidates per
-  // https://w3c.github.io/webrtc-pc/#attributes-1
-  virtual absl::optional<bool> can_trickle_ice_candidates() = 0;
-
   // Start RtcEventLog using an existing output-sink. Takes ownership of
   // |output| and passes it on to Call, which will take the ownership. If the
   // operation fails the output will be closed and deallocated. The event log

api/peer_connection_proxy.h

@@ -131,7 +131,6 @@ PROXY_METHOD0(IceConnectionState, ice_connection_state)
 PROXY_METHOD0(IceConnectionState, standardized_ice_connection_state)
 PROXY_METHOD0(PeerConnectionState, peer_connection_state)
 PROXY_METHOD0(IceGatheringState, ice_gathering_state)
-PROXY_METHOD0(absl::optional<bool>, can_trickle_ice_candidates)
 PROXY_METHOD2(bool,
               StartRtcEventLog,
               std::unique_ptr<RtcEventLogOutput>,

api/test/dummy_peer_connection.h

@@ -229,8 +229,6 @@ class DummyPeerConnection : public PeerConnectionInterface {
     return IceGatheringState();
   }
 
-  absl::optional<bool> can_trickle_ice_candidates() { return absl::nullopt; }
-
   bool StartRtcEventLog(std::unique_ptr<RtcEventLogOutput> output,
                         int64_t output_period_ms) override {
     return false;

api/test/mock_peerconnectioninterface.h

@@ -127,7 +127,6 @@ class MockPeerConnectionInterface
   MOCK_METHOD0(standardized_ice_connection_state, IceConnectionState());
   MOCK_METHOD0(peer_connection_state, PeerConnectionState());
   MOCK_METHOD0(ice_gathering_state, IceGatheringState());
-  MOCK_METHOD0(can_trickle_ice_candidates, absl::optional<bool>());
   MOCK_METHOD2(StartRtcEventLog,
                bool(std::unique_ptr<RtcEventLogOutput>, int64_t));
   MOCK_METHOD1(StartRtcEventLog, bool(std::unique_ptr<RtcEventLogOutput>));

pc/peer_connection.cc

@@ -2144,23 +2144,6 @@ PeerConnection::ice_gathering_state() {
   return ice_gathering_state_;
 }
 
-absl::optional<bool> PeerConnection::can_trickle_ice_candidates() {
-  RTC_DCHECK_RUN_ON(signaling_thread());
-  SessionDescriptionInterface* description = current_remote_description_.get();
-  if (!description) {
-    description = pending_remote_description_.get();
-  }
-  if (!description) {
-    return absl::nullopt;
-  }
-  // TODO(bugs.webrtc.org/7443): Change to retrieve from session-level option.
-  if (description->description()->transport_infos().size() < 1) {
-    return absl::nullopt;
-  }
-  return description->description()->transport_infos()[0].description.HasOption(
-      "trickle");
-}
-
 rtc::scoped_refptr<DataChannelInterface> PeerConnection::CreateDataChannel(
     const std::string& label,
     const DataChannelInit* config) {

pc/peer_connection.h

@@ -189,7 +189,6 @@ class PeerConnection : public PeerConnectionInternal,
   IceConnectionState standardized_ice_connection_state() override;
   PeerConnectionState peer_connection_state() override;
   IceGatheringState ice_gathering_state() override;
-  absl::optional<bool> can_trickle_ice_candidates() override;
 
   const SessionDescriptionInterface* local_description() const override;
   const SessionDescriptionInterface* remote_description() const override;

pc/peer_connection_interface_unittest.cc

@@ -3485,10 +3485,7 @@ TEST_P(PeerConnectionInterfaceTest, OffersAndAnswersHaveTrickleIceOption) {
   EXPECT_TRUE(desc->transport_infos()[1].description.HasOption("trickle"));
 
   // Apply the offer as a remote description, then create an answer.
-  EXPECT_FALSE(pc_->can_trickle_ice_candidates());
   EXPECT_TRUE(DoSetRemoteDescription(std::move(offer)));
-  ASSERT_TRUE(pc_->can_trickle_ice_candidates());
-  EXPECT_TRUE(*(pc_->can_trickle_ice_candidates()));
   std::unique_ptr<SessionDescriptionInterface> answer;
   ASSERT_TRUE(DoCreateAnswer(&answer, &options));
   desc = answer->description();

pc/test/fake_peer_connection_base.h

@@ -217,8 +217,6 @@ class FakePeerConnectionBase : public PeerConnectionInternal {
     return IceGatheringState::kIceGatheringNew;
   }
 
-  absl::optional<bool> can_trickle_ice_candidates() { return absl::nullopt; }
-
   bool StartRtcEventLog(std::unique_ptr<RtcEventLogOutput> output,
                         int64_t output_period_ms) override {
     return false;