Add WiFi SSID getter to NetworkChangeNotifier.

chrome/browser/prefetch/prefetch_browsertest.cc

Index: chrome/browser/prefetch/prefetch_browsertest.cc
diff --git a/chrome/browser/prefetch/prefetch_browsertest.cc b/chrome/browser/prefetch/prefetch_browsertest.cc
index 9ff446fc5e234fb753bdeb855f134b7c110889af..005e640d8daff65658e5aeb092bf8ab8e953c280 100644
--- a/chrome/browser/prefetch/prefetch_browsertest.cc
+++ b/chrome/browser/prefetch/prefetch_browsertest.cc
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <string>
+
 #include "base/command_line.h"
 #include "base/prefs/pref_service.h"
 #include "base/run_loop.h"
@@ -35,6 +37,7 @@ class MockNetworkChangeNotifierWIFI : public NetworkChangeNotifier {
   ConnectionType GetCurrentConnectionType() const override {
     return NetworkChangeNotifier::CONNECTION_WIFI;
   }
+  std::string GetCurrentWiFiSSID() const override { return ""; }
 };
 
 class MockNetworkChangeNotifier4G : public NetworkChangeNotifier {
@@ -42,6 +45,7 @@ class MockNetworkChangeNotifier4G : public NetworkChangeNotifier {
   ConnectionType GetCurrentConnectionType() const override {
     return NetworkChangeNotifier::CONNECTION_4G;
   }
+  std::string GetCurrentWiFiSSID() const override { return ""; }
 };
 
 class PrefetchBrowserTestBase : public InProcessBrowserTest {