Add interfaces for most major Blimp net components.

blimp/net/test_common.cc

Index: blimp/net/test_common.cc
diff --git a/blimp/net/test_common.cc b/blimp/net/test_common.cc
index 989d028ba6a7449c2c249f7482ee44ad1e9046ba..b9cad9d556c43018326b7a5109af383e8b1bd1e7 100644
--- a/blimp/net/test_common.cc
+++ b/blimp/net/test_common.cc
@@ -7,6 +7,7 @@
 #include <string>
 
 #include "base/sys_byteorder.h"
+#include "blimp/common/proto/blimp_message.pb.h"
 #include "blimp/net/common.h"
 #include "net/base/io_buffer.h"
 
@@ -16,6 +17,10 @@ MockStreamSocket::MockStreamSocket() {}
 
 MockStreamSocket::~MockStreamSocket() {}
 
+MockBlimpMessageProcessor::MockBlimpMessageProcessor() {}
+
+MockBlimpMessageProcessor::~MockBlimpMessageProcessor() {}
+
 std::string EncodeHeader(size_t size) {
   scoped_ptr<char[]> serialized(new char[kPacketHeaderSizeBytes]);
   uint32 net_size = base::HostToNet32(size);