Wire up FlexFEC in VideoEngine2.

webrtc/media/engine/fakewebrtccall.h

Index: webrtc/media/engine/fakewebrtccall.h
diff --git a/webrtc/media/engine/fakewebrtccall.h b/webrtc/media/engine/fakewebrtccall.h
index c6b67cfc064b463696c35486f48ffced06d61bd3..45258153f0f2521d7307bdd5708640571de6d6f6 100644
--- a/webrtc/media/engine/fakewebrtccall.h
+++ b/webrtc/media/engine/fakewebrtccall.h
@@ -196,6 +196,24 @@ class FakeVideoReceiveStream final : public webrtc::VideoReceiveStream {
   webrtc::VideoReceiveStream::Stats stats_;
 };
 
+class FakeFlexfecReceiveStream final : public webrtc::FlexfecReceiveStream {
+ public:
+  explicit FakeFlexfecReceiveStream(
+      const webrtc::FlexfecReceiveStream::Config& config);
+
+  const webrtc::FlexfecReceiveStream::Config& GetConfig();
+
+ private:
+  // webrtc::FlexfecReceiveStream implementation.
+  void Start() override;
+  void Stop() override;
+
+  webrtc::FlexfecReceiveStream::Stats GetStats() const override;
+
+  webrtc::FlexfecReceiveStream::Config config_;
+  bool receiving_;
+};
+
 class FakeCall final : public webrtc::Call, public webrtc::PacketReceiver {
  public:
   explicit FakeCall(const webrtc::Call::Config& config);
@@ -210,6 +228,8 @@ class FakeCall final : public webrtc::Call, public webrtc::PacketReceiver {
   const std::vector<FakeAudioReceiveStream*>& GetAudioReceiveStreams();
   const FakeAudioReceiveStream* GetAudioReceiveStream(uint32_t ssrc);
 
+  const std::vector<FakeFlexfecReceiveStream*>& GetFlexfecReceiveStreams();
+
   rtc::SentPacket last_sent_packet() const { return last_sent_packet_; }
 
   // This is useful if we care about the last media packet (with id populated)
@@ -277,6 +297,7 @@ class FakeCall final : public webrtc::Call, public webrtc::PacketReceiver {
   std::vector<FakeAudioSendStream*> audio_send_streams_;
   std::vector<FakeVideoReceiveStream*> video_receive_streams_;
   std::vector<FakeAudioReceiveStream*> audio_receive_streams_;
+  std::vector<FakeFlexfecReceiveStream*> flexfec_receive_streams_;
 
   int num_created_send_streams_;
   int num_created_receive_streams_;