Add a SigninAllowed policy.

chrome/browser/profiles/gaia_info_update_service.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/profiles/gaia_info_update_service.h"
 
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 46 matching lines @@
   profile_image_downloader_->Start();
 }
 
 // static
 bool GAIAInfoUpdateService::ShouldUseGAIAProfileInfo(Profile* profile) {
 #if defined(OS_CHROMEOS)
   return false;
 #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".
   if (CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kGaiaProfileInfo)) {
     return true;
   }
 
   // This feature is disable by default.
   return false;
@@ skipping 115 matching lines @@
   const base::TimeDelta update_delta = base::Time::Now() - last_updated_;
 
   base::TimeDelta delta;
   if (update_delta < base::TimeDelta() || update_delta > desired_delta)
     delta = base::TimeDelta::FromSeconds(kMinUpdateIntervalSeconds);
   else
     delta = desired_delta - update_delta;
 
   timer_.Start(FROM_HERE, delta, this, &GAIAInfoUpdateService::Update);
 }