sync: Introduce classes for per-type counters

sync/internal_api/public/sessions/type_debug_info_observer.cc

Index: sync/internal_api/public/sessions/type_debug_info_observer.cc
diff --git a/sync/engine/update_handler.cc b/sync/internal_api/public/sessions/type_debug_info_observer.cc
similarity index 55%
copy from sync/engine/update_handler.cc
copy to sync/internal_api/public/sessions/type_debug_info_observer.cc
index 308fee95bb1074c197b6973f38b49eb017d9ba7c..3255013901fc5df3e5f13304dd325a9ad3c7dd85 100644
--- a/sync/engine/update_handler.cc
+++ b/sync/internal_api/public/sessions/type_debug_info_observer.cc
@@ -2,13 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "sync/engine/update_handler.h"
+#include "sync/internal_api/public/sessions/type_debug_info_observer.h"
 
 namespace syncer {
 
-UpdateHandler::UpdateHandler() {}
+TypeDebugInfoObserver::TypeDebugInfoObserver() {}
 
-UpdateHandler::~UpdateHandler() {}
+TypeDebugInfoObserver::~TypeDebugInfoObserver() {}
 
 
 }  // namespace syncer