Stop leaking FlexfecReceiveStream objects after call shutdown.

webrtc/media/engine/webrtcvideoengine2_unittest.cc

Index: webrtc/media/engine/webrtcvideoengine2_unittest.cc
diff --git a/webrtc/media/engine/webrtcvideoengine2_unittest.cc b/webrtc/media/engine/webrtcvideoengine2_unittest.cc
index bf017670170b17566855a917ffd9df0c89777d02..e516c8f9bfaaccb24c9052ca7002142aa0f7adca 100644
--- a/webrtc/media/engine/webrtcvideoengine2_unittest.cc
+++ b/webrtc/media/engine/webrtcvideoengine2_unittest.cc
@@ -2424,6 +2424,27 @@ TEST_F(WebRtcVideoChannel2FlexfecTest, SetSendCodecsWithoutFec) {
   EXPECT_EQ(-1, config.rtp.flexfec.payload_type);
 }
 
+TEST_F(WebRtcVideoChannel2FlexfecTest, SetRecvCodecsWithFec) {

[brandtr, 2017/01/20 15:04:50]

Here it is. This is a slightly simplified version of the test in 
https://cs.chromium.org/chromium/src/third_party/webrtc/media/engine/webrtcvi...

From the perspective of this bug, the point of this test is to exercise
~WebRtcVideoChannel2 when a FlexfecReceiveStream object has been created. I ran
it locally 10000 times with asan+lsan, but couldn't get any leak warnings.
Perhaps I didn't configure the sanitizers correctly.

The earlier test linked above should also have exercised ~WebRtcVideoChannel2,
but I haven't received any bug reports from that one either.

+  AddRecvStream(
+      CreatePrimaryWithFecFrStreamParams("cname", kSsrcs1[0], kFlexfecSsrc));
+  const std::list<FakeFlexfecReceiveStream>& streams =
+      fake_call_->GetFlexfecReceiveStreams();
+
+  cricket::VideoRecvParameters recv_parameters;
+  recv_parameters.codecs.push_back(GetEngineCodec("VP8"));
+  recv_parameters.codecs.push_back(GetEngineCodec("flexfec-03"));
+  ASSERT_TRUE(channel_->SetRecvParameters(recv_parameters));
+  ASSERT_EQ(1U, streams.size());
+  const FakeFlexfecReceiveStream& stream_with_recv_params = streams.front();
+  EXPECT_EQ(GetEngineCodec("flexfec-03").id,
+            stream_with_recv_params.GetConfig().payload_type);
+  EXPECT_EQ(kFlexfecSsrc, stream_with_recv_params.GetConfig().remote_ssrc);
+  EXPECT_EQ(1U,
+            stream_with_recv_params.GetConfig().protected_media_ssrcs.size());
+  EXPECT_EQ(kSsrcs1[0],
+            stream_with_recv_params.GetConfig().protected_media_ssrcs[0]);
+}
+
 TEST_F(WebRtcVideoChannel2Test,
        SetSendCodecRejectsRtxWithoutAssociatedPayloadType) {
   const int kUnusedPayloadType = 127;