[Sync] Split DirectoryChangeListener for thread-safety

chrome/chrome.gyp

Index: chrome/chrome.gyp
diff --git a/chrome/chrome.gyp b/chrome/chrome.gyp
index 5c7059460c87f7253afa24baceaa1bbc234ee664..9751d5974c5f7ae2f853bd134e03198da0bc0e8a 100644
--- a/chrome/chrome.gyp
+++ b/chrome/chrome.gyp
@@ -655,8 +655,8 @@
         'browser/sync/js_arg_list.cc',
         'browser/sync/js_arg_list.h',
         'browser/sync/js_backend.h',
-        'browser/sync/js_directory_change_listener.cc',
-        'browser/sync/js_directory_change_listener.h',
+        'browser/sync/js_transaction_observer.cc',
+        'browser/sync/js_transaction_observer.h',
         'browser/sync/js_event_details.cc',
         'browser/sync/js_event_details.h',
         'browser/sync/js_event_handler.h',
@@ -687,7 +687,7 @@
         'browser/sync/syncable/dir_open_result.h',
         'browser/sync/syncable/directory_backing_store.cc',
         'browser/sync/syncable/directory_backing_store.h',
-        'browser/sync/syncable/directory_change_listener.h',
+        'browser/sync/syncable/directory_change_delegate.h',
         'browser/sync/syncable/directory_event.h',
         'browser/sync/syncable/directory_manager.cc',
         'browser/sync/syncable/directory_manager.h',
@@ -706,11 +706,14 @@
         'browser/sync/syncable/syncable_id.h',
         'browser/sync/syncable/syncable_enum_conversions.cc',
         'browser/sync/syncable/syncable_enum_conversions.h',
+        'browser/sync/syncable/transaction_observer.h',
         'browser/sync/util/cryptographer.cc',
         'browser/sync/util/cryptographer.h',
         'browser/sync/util/dbgq.h',
         'browser/sync/util/extensions_activity_monitor.cc',
         'browser/sync/util/extensions_activity_monitor.h',
+        'browser/sync/util/logging.cc',
+        'browser/sync/util/logging.h',
         'browser/sync/util/nigori.cc',
         'browser/sync/util/nigori.h',
         'browser/sync/util/user_settings.cc',