Add the navigation redirect-chain to Sync sessions proto for offline analysis.

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 118 matching lines @@
     STATE_BLOCKED = 2;
   }
   // Whether access to the URL was allowed or blocked.
   optional BlockedState blocked_state = 18 [default=STATE_ALLOWED];
   // A list of category identifiers for the URL.
   repeated string content_pack_categories = 19;
   // The status code from the last navigation.
   optional int32 http_status_code = 20;
   // Referrer policy.
   optional int32 referrer_policy = 21;
+  // The redirections traversed during this navigation.
+  // The first entry corresponds to the original URL, and the last entry 
+  // corresponds the last URL that redirected (to the virtual_url).
+  repeated NavigationRedirect navigation_redirect = 22;
+  // Normally not present.
+  // The last URL traversed when different from the virtual_url.
+  optional string last_navigation_redirect_url = 23;

[haitaol1, 2014/01/17 23:52:23]

Can you confirm that this could happen, i.e. virtual_url is different from last
url in redirect chain?

[Donn Denman, 2014/01/18 01:30:19]

I have only seen this for urls like the new tab page.  I don't know if it would
every happen with redirection, but I was thinking it would be good to capture
the data in the case where it is different, so we would know.  Alternatively, we
could just remove this field.

 }
+
+// Navigation information for a single redirection within a single navigation.
+message NavigationRedirect {
+  // A URL that redirected while navigating to this virtual_url.
+  optional string url = 1;
+}