Remove all //blimp code.

blimp/common/proto/protocol_control.proto

-// 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.
-
-syntax = "proto2";
-
-option optimize_for = LITE_RUNTIME;
-
-package blimp;
-
-// Indicates the message-Id that the peer has most-recently processed.
-message CheckpointAckMessage {
-  optional int64 checkpoint_id = 1;
-}
-
-// Contains Client->Engine information to establish an authenticated connection.
-message StartConnectionMessage {
-  optional string client_auth_token = 1;
-  optional int32 protocol_version = 2;
-}
-
-// Indicates the reason for the peer ending the connection.
-message EndConnectionMessage {
-  enum Reason {
-    UNKNOWN = 0;
-    AUTHENTICATION_FAILED = 1;
-    PROTOCOL_MISMATCH = 2;
-  };
-  optional Reason reason = 1;
-}
-
-message ProtocolControlMessage {
-  oneof connection_message {
-    // Client => Server types.
-    StartConnectionMessage start_connection = 41;
-
-    // Bi-directional types.
-    CheckpointAckMessage checkpoint_ack = 42;
-    EndConnectionMessage end_connection = 43;
-  }
-}