Disable fetching of policy for login screen apps

chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_POLICY_DEVICE_CLOUD_POLICY_MANAGER_CHROMEOS_H_
 #define CHROME_BROWSER_CHROMEOS_POLICY_DEVICE_CLOUD_POLICY_MANAGER_CHROMEOS_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 158 matching lines @@
 
   std::unique_ptr<chromeos::attestation::AttestationPolicyObserver>
       attestation_policy_observer_;
 
   // Wrapper schema registry that will track the signin profile schema registry
   // once it is passed to this class.
   std::unique_ptr<ForwardingSchemaRegistry>
       signin_profile_forwarding_schema_registry_;
 
   // Whether the component cloud policy service should be created.
-  bool is_component_policy_enabled_ = true;
+  // TODO(emaxx): Change the default to true once both the client and the
+  // DMServer are ready for handling policy fetches with the
+  // google/chromeos/signinextension type. See crbug.com/666720,
+  // crbug.com/644304 for reference.
+  bool is_component_policy_enabled_ = false;
 
   base::ObserverList<Observer, true> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceCloudPolicyManagerChromeOS);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_CHROMEOS_POLICY_DEVICE_CLOUD_POLICY_MANAGER_CHROMEOS_H_