Implemented system tray UI for new account management.

ash/session_state_delegate.h

Index: ash/session_state_delegate.h
diff --git a/ash/session_state_delegate.h b/ash/session_state_delegate.h
index f0e7f22f42005c677abf234299ce8a4955a7c278..f0d6ec69d952e9a9c949d561d708ada7e92c6b2b 100644
--- a/ash/session_state_delegate.h
+++ b/ash/session_state_delegate.h
@@ -94,6 +94,12 @@ class ASH_EXPORT SessionStateDelegate {
   virtual const base::string16 GetUserDisplayName(
       MultiProfileIndex index) const = 0;
 
+  // Gets the given name of the user with |index|. An empty string can be
+  // returned if the given name of the user is unknown.
+  // Note that |index| can at maximum be |NumberOfLoggedInUsers() - 1|.
+  virtual const base::string16 GetUserGivenName(
+      MultiProfileIndex index) const = 0;
+
   // Gets the display email address for the user with the given |index|.
   // The display email address might contains some periods in the email name
   // as well as capitalized letters. For example: "Foo.Bar@mock.com".