Remove candidates when doing continual gathering

webrtc/api/webrtcsession_unittest.cc

Index: webrtc/api/webrtcsession_unittest.cc
diff --git a/webrtc/api/webrtcsession_unittest.cc b/webrtc/api/webrtcsession_unittest.cc
index f503db3e130d35e457a2c2293efd5780092e5777..a99b1eeeeb335a15bb99746c66a81dc52a46d7de 100644
--- a/webrtc/api/webrtcsession_unittest.cc
+++ b/webrtc/api/webrtcsession_unittest.cc
@@ -191,6 +191,9 @@ class MockIceObserver : public webrtc::IceObserver {
     EXPECT_NE(PeerConnectionInterface::kIceGatheringNew, ice_gathering_state_);
   }
 
+  // Some local candidates are removed.
+  void OnIceCandidatesRemoved(const cricket::Candidates& candidates) {}
+
   bool oncandidatesready_;
   std::vector<cricket::Candidate> mline_0_candidates_;
   std::vector<cricket::Candidate> mline_1_candidates_;