Refactor BlimpConnection to TCPConnection

blimp/net/blimp_transport.h

Index: blimp/net/blimp_transport.h
diff --git a/blimp/net/blimp_transport.h b/blimp/net/blimp_transport.h
index 5d06632b2e9af0d5bc18c62f8af78c167922c177..6a7d9d5718e90d42eb64ce442707b31fbab3eb32 100644
--- a/blimp/net/blimp_transport.h
+++ b/blimp/net/blimp_transport.h
@@ -9,11 +9,11 @@
 #include <string>
 
 #include "net/base/completion_callback.h"
+#include "net/base/ip_endpoint.h"
 
 namespace blimp {
 
 class BlimpConnection;
-class MessagePort;
 
 // An interface which encapsulates the transport-specific code for
 // establishing network connections between the client and engine.
@@ -26,18 +26,27 @@ class BlimpTransport {
   // Initiate or listen for a connection.
   //
   // |callback| is passed net::OK if a connection was successfully
-  // established. The connection's MessagePort can then be taken by calling
-  // TakeMessagePort().
+  // established.
   // All other values indicate a connection error.
   virtual void Connect(const net::CompletionCallback& callback) = 0;
 
-  // Returns the MessagePort of a successfully established connection.
-  virtual std::unique_ptr<MessagePort> TakeMessagePort() = 0;
+  // Creates a new |BlimpConnection| for the specific |BlimpTransport|
+  // implementation. Call this once the |Connect|'s callback returns net::OK.

[Garrett Casto, 2016/10/26 23:43:48]

Nit: "Must not be called unless |callback| from Connect() returns net::OK". I
think that it's generally better to describe what a caller is allowed to do, not
what they have to do (given that they don't actually _have_ to call
MakeConnection()).

[perumaal, 2016/10/27 00:16:04]

Good point. 

+  virtual std::unique_ptr<BlimpConnection> MakeConnection() = 0;
 
   // Gets the transport name, e.g. "TCP", "SSL", "mock", etc.
   virtual const char* GetName() const = 0;
 };
 
+// Interface specific to engine transport on top of generic |BlimpTransport|.
+class BlimpEngineTransport : public BlimpTransport {

[Garrett Casto, 2016/10/26 23:43:48]

Given the rest of this directory, I would assume this would be in it's own file
(blimp_engine_transport.h)

[perumaal, 2016/10/27 00:16:05]

Done.

+ public:
+  ~BlimpEngineTransport() override {}
+
+  // Obtains the local listening address.
+  virtual void GetLocalAddress(net::IPEndPoint* ip_address) const = 0;
+};
+
 }  // namespace blimp
 
 #endif  // BLIMP_NET_BLIMP_TRANSPORT_H_