[Sync] Add a new global_id field to sync_pb::TabNavigation

sync/protocol/session_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 sessions.
 
 // Update proto_value_conversions{.h,.cc,_unittest.cc} if you change
 // any fields in this file.
 
 syntax = "proto2";
@@ skipping 93 matching lines @@
   // Content state is an opaque blob created by WebKit that represents the
   // state of the page. This includes form entries and scroll position for each
   // frame.
   optional string state = 5;
   // The core transition type.
   optional SyncEnums.PageTransition page_transition = 6 [default = TYPED];
   // If this transition was triggered by a redirect, the redirect type.
   optional SyncEnums.PageTransitionRedirectType redirect_type = 7;
   // The unique navigation id (within this client).
   optional int32 unique_id = 8;
-  // Timestamp for when this navigation last occurred (in client time).
-  // If the user goes back/foward in history the timestamp may refresh.
-  optional int64 timestamp = 9;
   // User used the Forward or Back button to navigate among browsing history.
   optional bool navigation_forward_back = 10;
   // User used the address bar to trigger this navigation.
   optional bool navigation_from_address_bar = 11;
   // User is navigating to the home page.
   optional bool navigation_home_page = 12;
   // The beginning of a navigation chain.
   optional bool navigation_chain_start = 13;
   // The last transition in a redirect chain.
   optional bool navigation_chain_end = 14;
+
+  // Timestamp for when this navigation last occurred (in milliseconds
+  // since the Unix epoch according to the local clock).  Deprecated
+  // in favor of local_timestamp (which has microsecond resolution).
+  optional int64 timestamp_deprecated = 9;
+  // Timestamp for when this navigation last occurred (in microseconds
+  // since the Windows epoch according to the local clock).
+  optional int64 local_timestamp = 15;

[Nicolas Zea, 2012/10/08 22:20:56]

local_timestamp_us?

Also, any reason why we're switching to windows epoch from unix epoch?

 }
-