Simplify message parsing.

remoting/protocol/channel_dispatcher_base.h

Index: remoting/protocol/channel_dispatcher_base.h
diff --git a/remoting/protocol/channel_dispatcher_base.h b/remoting/protocol/channel_dispatcher_base.h
index 06d2c79f533e3f7d324eada10f0b2611d5e965db..c8eedebfa9901f61584dadc068f31ed25f0715d2 100644
--- a/remoting/protocol/channel_dispatcher_base.h
+++ b/remoting/protocol/channel_dispatcher_base.h
@@ -55,7 +55,9 @@ class ChannelDispatcherBase {
   explicit ChannelDispatcherBase(const char* channel_name);
 
   BufferedSocketWriter* writer() { return &writer_; }
-  MessageReader* reader() { return &reader_; }
+
+  // Should be overridden in child classes to handle incoming messages.
+  virtual void OnIncomingMessage(scoped_ptr<CompoundBuffer> message);

[Jamie, 2016/01/30 00:56:27]

Is the case for not overriding this sufficiently common to warrant it being
non-pure-virtual? If it's rare, I think I'd prefer this to be pure-virtual with
explicit no-op overrides where appropriate.

If it's common, then default handling in the base class makes sense (though I'd
argue that "may" would be more appropriate than "should" in the comment in that
case).

[Sergey Ulanov, 2016/01/30 02:15:48]

Some channels are one-directional (events and audio). The dispatcher on the
sending side doesn't need to override this method.
Anyway, I don't care one way or the other. Made it pure virtual.

 
  private:
   void OnChannelReady(scoped_ptr<P2PStreamSocket> socket);