Add source column to chrome://policy showing the origins of policies.

chrome/browser/chromeos/policy/device_policy_decoder_chromeos.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/chromeos/policy/device_policy_decoder_chromeos.h"
 
 #include <limits>
 #include <string>
 
 #include "base/callback.h"
@@ skipping 722 matching lines @@
           NULL);
     }
   }
 
   if (policy.has_extension_cache_size()) {
     const em::ExtensionCacheSizeProto& container(policy.extension_cache_size());
     if (container.has_extension_cache_size()) {
       policies->Set(
           key::kExtensionCacheSize, POLICY_LEVEL_MANDATORY,
           POLICY_SCOPE_MACHINE,
-          DecodeIntegerValue(container.extension_cache_size()).release(),
-          nullptr);
+          DecodeIntegerValue(container.extension_cache_size()).release(), NULL);

[Thiemo Nagel, 2015/09/01 17:40:36]

Don't convert code from nullptr to NULL (only the other way round).

[fhorschig, 2015/09/04 06:53:53]

Done. (FYI: These two calls of "policies->Set" are now again the only 2 of all
55 which use nullptr instead of NULL)

[Thiemo Nagel, 2015/09/04 20:15:53]

Feel free to submit a CL to convert the remaining 53.  Cf.
http://chromium-cpp.appspot.com/ and
https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/4mijeJHzxLg.

     }
   }
 
   if (policy.has_login_screen_domain_auto_complete()) {
     const em::LoginScreenDomainAutoCompleteProto& container(
         policy.login_screen_domain_auto_complete());
     policies->Set(
         key::kDeviceLoginScreenDomainAutoComplete, POLICY_LEVEL_MANDATORY,
         POLICY_SCOPE_MACHINE,
         new base::StringValue(container.login_screen_domain_auto_complete()),
-        nullptr);
+        NULL);
   }
 }
 
 }  // namespace
 
 void DecodeDevicePolicy(const em::ChromeDeviceSettingsProto& policy,
                         PolicyMap* policies) {
   // Decode the various groups of policies.
   DecodeLoginPolicies(policy, policies);
   DecodeNetworkPolicies(policy, policies);
   DecodeReportingPolicies(policy, policies);
   DecodeAutoUpdatePolicies(policy, policies);
   DecodeAccessibilityPolicies(policy, policies);
   DecodeGenericPolicies(policy, policies);
 }
 
 }  // namespace policy