[CrOS Tether] Add KeepAliveTickleResponse messages to both the proto file and MessageWrapper.

chromeos/components/tether/message_wrapper_unittest.cc

 // Copyright 2017 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 "chromeos/components/tether/message_wrapper.h"
 
 #include <sstream>
 
 #include "base/base64url.h"
 #include "base/logging.h"
@@ skipping 85 matching lines @@
                         MessageType::DISCONNECT_TETHERING_REQUEST);
 }
 
 TEST_F(MessageWrapperTest, TestToAndFromRawMessage_KeepAliveTickle) {
   KeepAliveTickle tickle;
 
   MessageWrapper wrapper(tickle);
   VerifyProtoConversion(&tickle, wrapper, MessageType::KEEP_ALIVE_TICKLE);
 }
 
+TEST_F(MessageWrapperTest, TestToAndFromRawMessage_KeepAliveTickleResponse) {
+  KeepAliveTickleResponse response;
+
+  MessageWrapper wrapper(response);
+  VerifyProtoConversion(&response, wrapper,
+                        MessageType::KEEP_ALIVE_TICKLE_RESPONSE);
+}
+
 TEST_F(MessageWrapperTest, TestToAndFromRawMessage_TetherAvailabilityRequest) {
   TetherAvailabilityRequest request;
 
   MessageWrapper wrapper(request);
   VerifyProtoConversion(&request, wrapper,
                         MessageType::TETHER_AVAILABILITY_REQUEST);
 }
 
 TEST_F(MessageWrapperTest, TestToAndFromRawMessage_TetherAvailabilityResponse) {
   TetherAvailabilityResponse response = CreateTetherAvailabilityResponse();
@@ skipping 73 matching lines @@
   EXPECT_TRUE(wrapper);
   EXPECT_EQ(MessageType::TETHER_AVAILABILITY_RESPONSE,
             wrapper->GetMessageType());
   EXPECT_EQ(response.SerializeAsString(),
             wrapper->GetProto()->SerializeAsString());
 }
 
 }  // namespace tether
 
 }  // namespace cryptauth