Add support for dynamic channels in WebrtcTransport.

remoting/protocol/client_video_dispatcher_unittest.cc

Index: remoting/protocol/client_video_dispatcher_unittest.cc
diff --git a/remoting/protocol/client_video_dispatcher_unittest.cc b/remoting/protocol/client_video_dispatcher_unittest.cc
index f847ef96c41fb363a02b714fe2700b3dd9ef4bcf..e26ca45d4bba9566b32911f525b6275d9525d704 100644
--- a/remoting/protocol/client_video_dispatcher_unittest.cc
+++ b/remoting/protocol/client_video_dispatcher_unittest.cc
@@ -34,6 +34,7 @@ class ClientVideoDispatcherTest : public testing::Test,
 
   // ChannelDispatcherBase::EventHandler interface.
   void OnChannelInitialized(ChannelDispatcherBase* channel_dispatcher) override;
+  void OnChannelClosed(ChannelDispatcherBase* channel_dispatcher) override;
 
  protected:
   void OnChannelError(int error);
@@ -96,6 +97,12 @@ void ClientVideoDispatcherTest::OnChannelInitialized(
   initialized_ = true;
 }
 
+void ClientVideoDispatcherTest::OnChannelClosed(
+    ChannelDispatcherBase* channel_dispatcher) {
+  // Don't expect channels to be closed.
+  FAIL();
+}
+
 void ClientVideoDispatcherTest::OnChannelError(int error) {
   // Don't expect channel creation to fail.
   FAIL();