Create new class "CastTransport", which encapsulates the message read and write event loops.

extensions/browser/api/cast_channel/cast_channel_api.h

Index: extensions/browser/api/cast_channel/cast_channel_api.h
diff --git a/extensions/browser/api/cast_channel/cast_channel_api.h b/extensions/browser/api/cast_channel/cast_channel_api.h
index ebb3173a54e97c02d9f1877b25df8fc3bf126bb9..e2ac03e8d3bf60cc6188c2d21b133d2e75385966 100644
--- a/extensions/browser/api/cast_channel/cast_channel_api.h
+++ b/extensions/browser/api/cast_channel/cast_channel_api.h
@@ -48,7 +48,8 @@ class CastChannelAPI : public BrowserContextKeyedAPI,
   // BrowserContextKeyedAPI implementation.
   static BrowserContextKeyedAPIFactory<CastChannelAPI>* GetFactoryInstance();
 
-  // Returns a new CastSocket that connects to |ip_endpoint| with authentication
+  // Returns a new CastSocket that connects to |ip_endpoint| with
+  // authentication

[Wez, 2014/09/25 02:09:15]

nit: This can be un-wrapped now that CastSocket is shorter!

[Kevin M, 2014/09/25 17:53:04]

Done.

   // |channel_auth| and is to be owned by |extension_id|.
   scoped_ptr<cast_channel::CastSocket> CreateCastSocket(
       const std::string& extension_id,
@@ -58,7 +59,8 @@ class CastChannelAPI : public BrowserContextKeyedAPI,
 
   // Returns a pointer to the Logger member variable.
   // TODO(imcheng): Consider whether it is possible for this class to own the
-  // CastSockets and make this class the sole owner of Logger. Alternatively,
+  // CastSockets and make this class the sole owner of Logger.
+  // Alternatively,

[Wez, 2014/09/25 02:09:15]

nit: And this!

[Kevin M, 2014/09/25 17:53:04]

This function's still useful, the Open and GetLogs functions rely on it to get
the logger instance.

   // consider making Logger not ref-counted by passing a weak
   // reference of Logger to the CastSockets instead.
   scoped_refptr<cast_channel::Logger> GetLogger();