Initial CL for Data Saver (Flywheel) prompt when cellular network detected

chromeos/network/network_state_handler_observer.cc

 // Copyright (c) 2012 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/network/network_state_handler_observer.h"
 
 namespace chromeos {
 
+const char NetworkStateHandlerObserver::kDebugDataSaverNetworkPath[] =
+    "debug-datasaver-network-path";
+
 NetworkStateHandlerObserver::NetworkStateHandlerObserver() {
 }
 
 NetworkStateHandlerObserver::~NetworkStateHandlerObserver() {
 }
 
 void NetworkStateHandlerObserver::NetworkListChanged() {
 }
 
 void NetworkStateHandlerObserver::DeviceListChanged() {
@@ skipping 15 matching lines @@
     const chromeos::DeviceState* device) {
 }
 
 void NetworkStateHandlerObserver::ScanCompleted(const DeviceState* device) {
 }
 
 void NetworkStateHandlerObserver::IsShuttingDown() {
 }
 
 }  // namespace chromeos