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..4044b6e801622ab5fa01534312410575d3cbfded 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 {

[jdufault, 2016/08/16 17:55:02]

Is it possible to make these enums private?

[sammiequon, 2016/08/16 19:22:11]

Done.

+    AUTH_SUCCESS_PASSWORD = 0,
+    AUTH_SUCCESS_PIN,
+    AUTH_SUCCESS_COUNT
+  };
+
+  enum UnlockFailure {

[jdufault, 2016/08/16 17:55:02]

Do these need to be separate enums? Is it possible to just have

  enum UnlockType {
    AUTH_PASSWORD = 0,
    AUTH_PIN,
    AUTH_COUNT
  };

[sammiequon, 2016/08/16 19:22:11]

Done.

+    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.
@@ -167,7 +179,7 @@ class ScreenLocker : public AuthStatusConsumer {
   // True if the screen is locked, or false otherwise.  This changes
   // from false to true, but will never change from true to
   // false. Instead, ScreenLocker object gets deleted when unlocked.
-  bool locked_;
+  bool locked_ = false;
 
   // Reference to the single instance of the screen locker object.
   // This is used to make sure there is only one screen locker instance.
@@ -183,7 +195,10 @@ class ScreenLocker : public AuthStatusConsumer {
   AuthStatusConsumer* auth_status_consumer_;
 
   // Number of bad login attempts in a row.
-  int incorrect_passwords_count_;
+  int incorrect_passwords_count_ = 0;
+
+  // Whether the last password entered was a pin or not.
+  bool is_pin_attempt_ = false;
 
   // Copy of parameters passed to last call of OnLoginSuccess for usage in
   // UnlockOnLoginSuccess().