Reporting: Use const& for origin_filter callback.

Just saving a copy.

[email protected]

Bug: 
Change-Id: I73898db71fa94ccad92d70eac8d6c40fa175f725
Reviewed-on: https://chromium-review.googlesource.com/829593
Commit-Queue: Julia Tuttle <[email protected]>
Reviewed-by: Miriam Gershenson <[email protected]>
Cr-Commit-Position: refs/heads/master@{#525117}
diff --git a/net/reporting/reporting_service.h b/net/reporting/reporting_service.h
index 71f775a..aa7dc40e 100644
--- a/net/reporting/reporting_service.h
+++ b/net/reporting/reporting_service.h
@@ -64,7 +64,7 @@
   // ReportingBrowsingDataRemover for more details.
   virtual void RemoveBrowsingData(
       int data_type_mask,
-      base::RepeatingCallback<bool(const GURL&)> origin_filter) = 0;
+      const base::RepeatingCallback<bool(const GURL&)>& origin_filter) = 0;
 
   // Checks whether |request| is a Reporting upload, to avoid loops of reporting
   // about report uploads.