GetAccountIdFromProfile() should not return an empty account id if a valid profile is provided.

chrome/browser/ui/ash/multi_user/multi_user_util.cc

Index: chrome/browser/ui/ash/multi_user/multi_user_util.cc
diff --git a/chrome/browser/ui/ash/multi_user/multi_user_util.cc b/chrome/browser/ui/ash/multi_user/multi_user_util.cc
index c273936497f34c1a98de094902c66fd42c4c2eea..5e4d80cfc8ce40d01b8046f314a83ffeba8ba471 100644
--- a/chrome/browser/ui/ash/multi_user/multi_user_util.cc
+++ b/chrome/browser/ui/ash/multi_user/multi_user_util.cc
@@ -23,6 +23,19 @@
 namespace multi_user_util {
 
 AccountId GetAccountIdFromProfile(Profile* profile) {
+#if defined(OS_CHROMEOS)
+  // If in a session the refresh token is revoked, GetProfileUserName() might
+  // returns an empty user email which will cause GetAccountIdFromProfile()
+  // returns an empty account id, which might cause wired behaviors or crash.

[Roger Tawa OOO till Jul 10th, 2016/05/05 14:27:20]

wired --> weird

[xdai1, 2016/05/05 18:08:47]

Done.

+  // Note: If the refresh token is revoked because the user changes his GAIA
+  // password, we will force log out the user within 120 seconds. See crbug.com/
+  // 587318 for more detail.
+  const user_manager::User* user =
+      chromeos::ProfileHelper::Get()->GetUserByProfile(
+          profile->GetOriginalProfile());
+  return user ? user->GetAccountId() : EmptyAccountId();
+#endif
+
   return GetAccountIdFromEmail(
       profile->GetOriginalProfile()->GetProfileUserName());

[Roger Tawa OOO till Jul 10th, 2016/05/05 14:27:20]

Shouldn't lines 39-40 be wrapped in an #else?  This is now dead code on cros.

[xdai1, 2016/05/05 18:08:47]

Done. I thought it should be fine to not use a #elif since it always returns on
line 36 on Chrome OS.

 }
@@ -48,19 +61,6 @@ Profile* GetProfileFromAccountId(const AccountId& account_id) {
       return *profile_iterator;
   }
 
-#if defined(OS_CHROMEOS)
-  // If in a session the refresh token is revoked, GetAccountIdFromProfile()
-  // returns an empty account id which will cause the profile not being fetched
-  // properly. In this case we fall back to use GetProfileByUser() function.
-  // Note: If the refresh token is revoked because the user changes his GAIA
-  // password, we will force log out the user within 120 seconds. See crbug.com/
-  // 587318 for more detail.
-  const user_manager::User* user =
-      user_manager::UserManager::Get()->FindUser(account_id);
-  if (user)
-    return chromeos::ProfileHelper::Get()->GetProfileByUser(user);
-#endif
-
   return nullptr;
 }