Add a SigninAllowed policy.

chrome/browser/profiles/gaia_info_update_service.cc

Index: chrome/browser/profiles/gaia_info_update_service.cc
diff --git a/chrome/browser/profiles/gaia_info_update_service.cc b/chrome/browser/profiles/gaia_info_update_service.cc
index bb0e4085441caa44b702f2d132c1bb07e886c23e..ee04f00ddf7ab17f593c1dce797861a5eff3199e 100644
--- a/chrome/browser/profiles/gaia_info_update_service.cc
+++ b/chrome/browser/profiles/gaia_info_update_service.cc
@@ -64,7 +64,8 @@ bool GAIAInfoUpdateService::ShouldUseGAIAProfileInfo(Profile* profile) {
 #endif
 
   // Sync must be allowed.
-  if (!profile->GetOriginalProfile()->IsSyncAccessible())
+  if (!profile->GetOriginalProfile()->IsSyncAccessible() ||
+      !profile->GetOriginalProfile()->IsSigninAllowed())

[sail, 2013/02/08 20:18:57]

Why this change?

[Adrian Kuegel, 2013/02/11 16:47:30]

I thought that "No Signin" should imply "No Sync" as well. But it seems to be
already covered since with a policy change that disallows signin we also sign
out automatically, so I removed the change.

     return false;
 
   // To enable this feature for testing pass "--gaia-profile-info".