UMA for pin unlock success/failure.

chrome/browser/chromeos/login/signin/device_id_browsertest.cc

Index: chrome/browser/chromeos/login/signin/device_id_browsertest.cc
diff --git a/chrome/browser/chromeos/login/signin/device_id_browsertest.cc b/chrome/browser/chromeos/login/signin/device_id_browsertest.cc
index 4934033ee1cddc7a011282812a9a3b98a5aa8253..77b5ff4fbd9b3723e0617e0c4088df7b4fbbc7b3 100644
--- a/chrome/browser/chromeos/login/signin/device_id_browsertest.cc
+++ b/chrome/browser/chromeos/login/signin/device_id_browsertest.cc
@@ -116,9 +116,9 @@ class DeviceIDTest : public OobeBaseTest,
   void SignInOffline(const std::string& user_id, const std::string& password) {
     WaitForSigninScreen();
 
-    JS().ExecuteAsync(
-        base::StringPrintf("chrome.send('authenticateUser', ['%s', '%s'])",
-                           user_id.c_str(), password.c_str()));
+    JS().ExecuteAsync(base::StringPrintf(
+        "chrome.send('authenticateUser', ['%s', '%s', false])", user_id.c_str(),
+        password.c_str()));
     WaitForSessionStart();
   }