Move PolicyLoaderMac::CreateValueFromProperty to a generic file.

components/policy/policy_common.gypi

Index: components/policy/policy_common.gypi
diff --git a/components/policy/policy_common.gypi b/components/policy/policy_common.gypi
index 0b75ebeb48d195f535d1d9c246d2caf46a911219..c222ce8b507da91542c80d0a52af1ad8a667206e 100644
--- a/components/policy/policy_common.gypi
+++ b/components/policy/policy_common.gypi
@@ -92,6 +92,8 @@
         'core/common/external_data_manager.h',
         'core/common/forwarding_policy_provider.cc',
         'core/common/forwarding_policy_provider.h',
+        'core/common/mac_util.cc',
+        'core/common/mac_util.h',
         'core/common/policy_bundle.cc',
         'core/common/policy_bundle.h',
         'core/common/policy_details.h',
@@ -175,6 +177,12 @@
             'core/common/cloud/user_cloud_policy_store.h',
           ],
         }],
+        ['OS!="ios" and OS!="mac"', {
+          'sources!': [
+            'core/common/mac_util.cc',
+            'core/common/mac_util.h',
+          ],
+        }],
       ],
     }, {  # configuration_policy==0
       # Some of the policy code is always enabled, so that other parts of