Add gaia_id to ProfileInfoCache.

chrome/browser/profiles/avatar_menu.h

Index: chrome/browser/profiles/avatar_menu.h
diff --git a/chrome/browser/profiles/avatar_menu.h b/chrome/browser/profiles/avatar_menu.h
index ee6b3d6f1b400e27720b1557613c018251ef25e9..a4154bf3c698290dce5a1372a261358be9f49232 100644
--- a/chrome/browser/profiles/avatar_menu.h
+++ b/chrome/browser/profiles/avatar_menu.h
@@ -56,8 +56,8 @@ class AvatarMenu :
     // The name of this profile.
     base::string16 name;
 
-    // A string representing the sync state of the profile.
-    base::string16 sync_state;
+    // A string representing the username of the profile, if signed in.

[noms (inactive), 2015/05/06 01:05:54]

nit: can you add an extra "; empty otherwise"? 

[Roger Tawa OOO till Jul 10th, 2015/05/11 16:09:57]

Done.

+    base::string16 username;
 
     // Whether or not the current profile is signed in. If true, |sync_state| is
     // expected to be the email of the signed in user.
@@ -157,7 +157,7 @@ class AvatarMenu :
       const base::string16& profile_name) override;
   void OnProfileNameChanged(const base::FilePath& profile_path,
       const base::string16& old_profile_name) override;
-  void OnProfileUserNameChanged(const base::FilePath& profile_path) override;
+  void OnProfileAuthInfoChanged(const base::FilePath& profile_path) override;
   void OnProfileAvatarChanged(const base::FilePath& profile_path) override;
   void OnProfileHighResAvatarLoaded(
       const base::FilePath& profile_path) override;