UMA for pin unlock success/failure.

chrome/browser/chromeos/login/lock/screen_locker.h

Index: chrome/browser/chromeos/login/lock/screen_locker.h
diff --git a/chrome/browser/chromeos/login/lock/screen_locker.h b/chrome/browser/chromeos/login/lock/screen_locker.h
index 856162047e922dc4e36fb28e303bbc31459e5e23..02f8a93c12f003ec221262266e6e061f37c0e49b 100644
--- a/chrome/browser/chromeos/login/lock/screen_locker.h
+++ b/chrome/browser/chromeos/login/lock/screen_locker.h
@@ -49,6 +49,18 @@ class WebUIScreenLockerTester;
 // instance of itself which will be deleted when the system is unlocked.
 class ScreenLocker : public AuthStatusConsumer {
  public:
+  enum UnlockSuccess {
+    AUTH_SUCCESS_PASSWORD = 0,
+    AUTH_SUCCESS_PIN,
+    AUTH_SUCCESS_COUNT
+  };
+
+  enum UnlockFailure {
+    AUTH_FAILURE_PASSWORD = 0,
+    AUTH_FAILURE_PIN,
+    AUTH_FAILURE_COUNT
+  };
+
   explicit ScreenLocker(const user_manager::UserList& users);
 
   // Returns the default instance if it has been created.
@@ -185,6 +197,9 @@ class ScreenLocker : public AuthStatusConsumer {
   // Number of bad login attempts in a row.
   int incorrect_passwords_count_;
 
+  // Whether the last password entered was a pin or not.
+  bool is_pin_attempt_;
+
   // Copy of parameters passed to last call of OnLoginSuccess for usage in
   // UnlockOnLoginSuccess().
   std::unique_ptr<AuthenticationParametersCapture> authentication_capture_;