Add interfaces for most major Blimp net components.

blimp/net/BUILD.gn

Index: blimp/net/BUILD.gn
diff --git a/blimp/net/BUILD.gn b/blimp/net/BUILD.gn
index 1b4da841c3e441cf3029d6d9e8491c7320115c6b..d05575118839cb9113b8afeedc033c506f68d18e 100644
--- a/blimp/net/BUILD.gn
+++ b/blimp/net/BUILD.gn
@@ -6,13 +6,24 @@ component("blimp_net") {
   sources = [
     "blimp_connection.cc",
     "blimp_connection.h",
+    "blimp_message_ack_observer.h",
+    "blimp_message_buffer.cc",
+    "blimp_message_buffer.h",
     "blimp_message_dispatcher.cc",
     "blimp_message_dispatcher.h",
+    "blimp_message_multiplexer.cc",
+    "blimp_message_multiplexer.h",
+    "blimp_message_processor.h",
     "blimp_message_receiver.h",
     "blimp_net_export.h",
     "blimp_transport.h",
+    "client_connection_manager.cc",
+    "client_connection_manager.h",
     "common.cc",
     "common.h",
+    "connection_handler.h",
+    "engine_connection_manager.cc",
+    "engine_connection_manager.h",
     "packet_reader.cc",
     "packet_reader.h",
     "packet_writer.cc",