Replace string16 with base::string16.

chrome/browser/chromeos/policy/device_local_account_browsertest.cc

Index: chrome/browser/chromeos/policy/device_local_account_browsertest.cc
diff --git a/chrome/browser/chromeos/policy/device_local_account_browsertest.cc b/chrome/browser/chromeos/policy/device_local_account_browsertest.cc
index 2015aabe595516d27aa231611cc97d3e9ff359fc..a505536b59b398d3789eb05bac765975803d3957 100644
--- a/chrome/browser/chromeos/policy/device_local_account_browsertest.cc
+++ b/chrome/browser/chromeos/policy/device_local_account_browsertest.cc
@@ -246,8 +246,8 @@ bool DoesInstallSuccessReferToId(const std::string& id,
 bool DoesInstallFailureReferToId(const std::string& id,
                                  const content::NotificationSource& source,
                                  const content::NotificationDetails& details) {
-  return content::Details<const string16>(details)->find(UTF8ToUTF16(id)) !=
-      string16::npos;
+  return content::Details<const base::string16>(details)->find(UTF8ToUTF16(id)) !=
+      base::string16::npos;
 }
 
 scoped_ptr<net::FakeURLFetcher> RunCallbackAndReturnFakeURLFetcher(