Blimp: create MessageDispatcher class.

blimp/net/blimp_message_receiver.h

Index: blimp/net/blimp_message_receiver.h
diff --git a/blimp/net/blimp_message_receiver.h b/blimp/net/blimp_message_receiver.h
new file mode 100644
index 0000000000000000000000000000000000000000..170e7dfd3e1186c5055e316f637e278b80456b44
--- /dev/null
+++ b/blimp/net/blimp_message_receiver.h
@@ -0,0 +1,27 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BLIMP_NET_BLIMP_MESSAGE_RECEIVER_H_
+#define BLIMP_NET_BLIMP_MESSAGE_RECEIVER_H_
+
+namespace blimp {
+
+class BlimpMessage;
+
+// Abstract interface for classes that can receive BlimpMessages.

[Wez, 2015/10/09 23:15:34]

nit: I can see it's abstract; suggest just "Interface implemented by components
that process BlimpMessages."

[Kevin M, 2015/10/10 00:42:34]

Done.

+class BlimpMessageReceiver {
+ public:
+  virtual ~BlimpMessageReceiver() {}
+
+  // Receives |message| for processing.
+  // The handler is responsible for routing the call through the appropriate
+  // thread.
+  // Method will return false if |message| is invalid, which should cause the
+  // connection to be terminated.

[Wez, 2015/10/09 23:15:35]

nit: Make clear that the caller needs to terminate the connection - "should
cause the connection to be terminated" could mean that this class returning
false is expected to implicitly terminate it, but might not.

Also, this comment seems unnecessarily verbose - e.g. it mentions threading,
which has absolutely nothing to do with anything else mentioned in this header!
Suggest just:

"Processes the BlimpMessage, or returns false on error. Callers should e.g.
terminate the connection from which |message| was received."

[Kevin M, 2015/10/10 00:42:34]

Done.

+  virtual bool OnMessage(const BlimpMessage& message) = 0;

[Wez, 2015/10/09 23:15:34]

nit: OnBlimpMessage, for consistency, and 'cos OnMessage is super generic
sounding?

[Kevin M, 2015/10/10 00:42:34]

Done.

+};
+
+}  // namespace blimp
+
+#endif  // BLIMP_NET_BLIMP_MESSAGE_RECEIVER_H_