[Sync] Create new top-level sync/ directory

sync/protocol/typed_url_specifics.proto

 // Copyright (c) 2012 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.
 //
 // Sync protocol datatype extension for typed urls.
 
 // Update proto_value_conversions{.h,.cc,_unittest.cc} if you change
 // any fields in this file.
 
 syntax = "proto2";
@@ skipping 21 matching lines @@
   // The number of explicit navigations to this URL (excludes page reloads) -
   // deprecated as we no longer sync this (history code infers this from the
   // |visits| array).
   // optional int32 visited_count = 6; (deprecated)
   // Timestamps for all visits to this URL.
   repeated int64 visits = 7 [packed=true];
   // The PageTransition::Type for each of the visits in the |visit| array. Both
   // arrays must be the same length.
   repeated int32 visit_transitions = 8 [packed=true];
 }