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

components/policy_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <grit-part>
 
   <message name="IDS_POLICY_DM_STATUS_SUCCESS" desc="Message indicating a successful device management server call.">
     Request succeeded
   </message>
   <message name="IDS_POLICY_DM_STATUS_REQUEST_INVALID" desc="Message indicating a bad request to the enterprise server.">
     Invalid request or request parameters
   </message>
   <message name="IDS_POLICY_DM_STATUS_REQUEST_FAILED" desc="Message indicating the request to the enterprise server failed in the network.">
@@ skipping 273 matching lines @@
   </message>
   <message name="IDS_POLICY_HEADER_NAME" desc="Table header for the column in the policy table that contains the policy name.">
     Policy name
   </message>
   <message name="IDS_POLICY_HEADER_VALUE" desc="Table header for the column in the policy table that contains the policy value.">
     Policy value
   </message>
   <message name="IDS_POLICY_HEADER_STATUS" desc="Table header for the column in policy table that contains the policy status.">
     Status
   </message>
+  <message name="IDS_POLICY_HEADER_SOURCE" desc="Table header for the column in policy table that contains the policy source.">
+    Source
+  </message>
   <message name="IDS_POLICY_SHOW_EXPANDED_VALUE" desc="Text for the link that shows the policy value. Used when the policy value is too long to be always visible.">
     Show value
   </message>
   <message name="IDS_POLICY_HIDE_EXPANDED_VALUE" desc="Text for the link that hides the policy value. Used when the policy value is too long to be always visible.">
     Hide value
   </message>
   <message name="IDS_POLICY_SCOPE_USER" desc="Text displayed in the Applies to column when a policy applies to the current user only.">
     Current user
   </message>
   <if expr="not is_android and not chromeos">
     <message name="IDS_POLICY_SCOPE_DEVICE" desc="Text displayed in the Applies to column when a policy applies to everyone on the machine.">
       Machine
     </message>
   </if>
   <if expr="chromeos or is_android">
     <message name="IDS_POLICY_SCOPE_DEVICE" desc="Mobile: Text displayed in the Applies To column when a policy applies to everyone on the device.">
       Device
     </message>
   </if>
   <message name="IDS_POLICY_LEVEL_RECOMMENDED" desc="Text displayed in the Level column when a policy is recommended.">
     Recommended
   </message>
   <message name="IDS_POLICY_LEVEL_MANDATORY" desc="Text displayed in the Level column when a policy is mandatory.">
     Mandatory
   </message>
   <message name="IDS_POLICY_INVALID_BOOKMARK" desc="Text displayed in the status column when an entry of the ManagedBookmarks policy is not a valid bookmark.">
     Ignored invalid bookmark at index <ph name="ENTRY_INDEX">$1<ex>3</ex></ph>
   </message>
+  <message name="IDS_POLICY_SOURCE_ENTERPRISE_DEFAULT" desc="Indicates that a policy is set by default in an enterprise environment and can be overridden (for Chrome OS only).">
+    Enterprise default
+  </message>
+  <message name="IDS_POLICY_SOURCE_CLOUD" desc="Indicates that the policy originates from the cloud.">
+    Cloud
+  </message>
+  <message name="IDS_POLICY_SOURCE_PLATFORM" desc="Indicates that the policy is obtained from the local OS.">
+    Platform
+  </message>
+  <message name="IDS_POLICY_SOURCE_ENTERPRISE_OVERRIDE" desc="Indicates that a policy is enforced  in an enterprise environment and can not be overridden (for Chrome OS only).">
+    Enterprise override
+  </message>
 </grit-part>