[USS] Show USS counters in about:sync page

components/sync/driver/glue/sync_backend_host_impl.h

 // Copyright 2013 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.
 
 #ifndef COMPONENTS_SYNC_DRIVER_GLUE_SYNC_BACKEND_HOST_IMPL_H_
 #define COMPONENTS_SYNC_DRIVER_GLUE_SYNC_BACKEND_HOST_IMPL_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 200 matching lines @@
   // explicitly requested that we start forwarding these events.
   void HandleDirectoryUpdateCountersUpdatedOnFrontendLoop(
       syncer::ModelType type,
       const syncer::UpdateCounters& counters);
 
   // Forwards a directory status counter update to the frontend loop.  Will not
   // be called unless a call to EnableDirectoryTypeDebugInfoForwarding()
   // explicitly requested that we start forwarding these events.
   void HandleDirectoryStatusCountersUpdatedOnFrontendLoop(
       syncer::ModelType type,
-      const syncer::StatusCounters& counters);
+      std::unique_ptr<syncer::StatusCounters> counters);
 
   // Overwrites the kSyncInvalidationVersions preference with the most recent
   // set of invalidation versions for each type.
   void UpdateInvalidationVersions(
       const std::map<syncer::ModelType, int64_t>& invalidation_versions);
 
   sync_driver::SyncFrontend* frontend() { return frontend_; }
 
  private:
   friend class SyncBackendHostCore;
@@ skipping 137 matching lines @@
   bool invalidation_handler_registered_;
 
   base::WeakPtrFactory<SyncBackendHostImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncBackendHostImpl);
 };
 
 }  // namespace browser_sync
 
 #endif  // COMPONENTS_SYNC_DRIVER_GLUE_SYNC_BACKEND_HOST_IMPL_H_