A little cleanup in the p2ptransportchannel.

webrtc/p2p/base/transportchannel.h

Index: webrtc/p2p/base/transportchannel.h
diff --git a/webrtc/p2p/base/transportchannel.h b/webrtc/p2p/base/transportchannel.h
index 767a5f68bf2acd65e2ab7f3433b7a179e0af9536..ea18957ef369278a4c7f832b37873ec55765b82f 100644
--- a/webrtc/p2p/base/transportchannel.h
+++ b/webrtc/p2p/base/transportchannel.h
@@ -154,9 +154,6 @@ class TransportChannel : public sigslot::has_slots<> {
   std::string ToString() const;
 
  protected:
-  // TODO(honghaiz): Remove this once chromium's unit tests no longer call it.
-  void set_readable(bool readable) { set_receiving(readable); }
-
   // Sets the writable state, signaling if necessary.
   void set_writable(bool writable);