[USS] Show USS counters in about:sync page

components/sync/driver/glue/sync_backend_host_core.cc

Index: components/sync/driver/glue/sync_backend_host_core.cc
diff --git a/components/sync/driver/glue/sync_backend_host_core.cc b/components/sync/driver/glue/sync_backend_host_core.cc
index 6bf962a14e09b3ff6231476bc48b148181364e20..2c1be44339afa68eda17b560effe0a9486348ba6 100644
--- a/components/sync/driver/glue/sync_backend_host_core.cc
+++ b/components/sync/driver/glue/sync_backend_host_core.cc
@@ -305,11 +305,11 @@ void SyncBackendHostCore::OnUpdateCountersUpdated(
 
 void SyncBackendHostCore::OnStatusCountersUpdated(
     syncer::ModelType type,
-    const syncer::StatusCounters& counters) {
+    std::unique_ptr<syncer::StatusCounters> counters) {
   host_.Call(
       FROM_HERE,
       &SyncBackendHostImpl::HandleDirectoryStatusCountersUpdatedOnFrontendLoop,
-      type, counters);
+      type, base::Passed(&counters));
 }
 
 void SyncBackendHostCore::OnActionableError(