Add interfaces for most major Blimp net components.

blimp/net/blimp_message_output_buffer.cc

Index: blimp/net/blimp_message_output_buffer.cc
diff --git a/blimp/net/blimp_message_output_buffer.cc b/blimp/net/blimp_message_output_buffer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c97ee2de9bb667d92a16440934c4c51fd52982aa
--- /dev/null
+++ b/blimp/net/blimp_message_output_buffer.cc
@@ -0,0 +1,29 @@
+// 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.
+
+#include "blimp/net/blimp_message_output_buffer.h"
+
+#include "base/macros.h"
+
+namespace blimp {
+
+BlimpMessageOutputBuffer::BlimpMessageOutputBuffer() {
+  NOTIMPLEMENTED();
+}
+
+BlimpMessageOutputBuffer::~BlimpMessageOutputBuffer() {
+  NOTIMPLEMENTED();
+}
+
+void BlimpMessageOutputBuffer::ProcessMessage(
+    const BlimpMessage& message,
+    const net::CompletionCallback& callback) {
+  NOTIMPLEMENTED();
+}
+
+void BlimpMessageOutputBuffer::OnMessageCheckpoint(int64 message_id) {
+  NOTIMPLEMENTED();
+}
+
+}  // namespace blimp