UMA for pin unlock success/failure.

chromeos/login/auth/user_context.h

Index: chromeos/login/auth/user_context.h
diff --git a/chromeos/login/auth/user_context.h b/chromeos/login/auth/user_context.h
index 6f29645a9994499eef16aa36008da2e98f391145..16d217556347d0f0d710cb9fc6abf1b0b58e2946 100644
--- a/chromeos/login/auth/user_context.h
+++ b/chromeos/login/auth/user_context.h
@@ -55,6 +55,7 @@ class CHROMEOS_EXPORT UserContext {
   const std::string& GetAccessToken() const;
   const std::string& GetUserIDHash() const;
   bool IsUsingOAuth() const;
+  bool IsUsingPin() const;
   AuthFlow GetAuthFlow() const;
   user_manager::UserType GetUserType() const;
   const std::string& GetPublicSessionLocale() const;
@@ -71,6 +72,7 @@ class CHROMEOS_EXPORT UserContext {
   void SetAccessToken(const std::string& access_token);
   void SetUserIDHash(const std::string& user_id_hash);
   void SetIsUsingOAuth(bool is_using_oauth);
+  void SetIsUsingPin(bool is_using_pin);
   void SetAuthFlow(AuthFlow auth_flow);
   void SetUserType(user_manager::UserType user_type);
   void SetPublicSessionLocale(const std::string& locale);
@@ -88,6 +90,7 @@ class CHROMEOS_EXPORT UserContext {
   std::string access_token_;  // OAuthLogin scoped access token.
   std::string user_id_hash_;
   bool is_using_oauth_ = true;
+  bool is_using_pin_ = false;
   AuthFlow auth_flow_ = AUTH_FLOW_OFFLINE;
   user_manager::UserType user_type_ = user_manager::USER_TYPE_REGULAR;
   std::string public_session_locale_;