Remove extended attributes. The lame broken codepath in the DBS was causing

chrome/browser/sync/protocol/sync.proto

 // Copyright (c) 2009 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 for communication between sync client and server.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
 package sync_pb;
 
-// Used to store and send extended attributes, which are arbitrary
-// key value pairs.
-message ExtendedAttributes {
-  repeated group ExtendedAttribute = 1 {
-    required string key = 2;
-    required bytes value = 3;
-  }
-}
-
 // Used for inspecting how long we spent performing operations in different
 // backends. All times must be in millis.
 message ProfilingData {
   optional int64 meta_data_write_time = 1;
   optional int64 file_data_write_time = 2;
   optional int64 user_lookup_time = 3;
   optional int64 meta_data_read_time = 4;
   optional int64 file_data_read_time = 5;
   optional int64 total_request_time = 6;
 }
@@ skipping 141 matching lines @@
   // element resides. An empty string indicates that the element is the first
   // element in the parent.  This value is used during commits to specify
   // a relative position for a position change.  In the context of
   // a GetUpdatesMessage, |position_in_parent| is used instead to
   // communicate position.
   // Present only in CommitMessage.
   optional string insert_after_item_id = 16;
 
   // Arbitrary key/value pairs associated with this item.
   // Present in both GetUpdatesResponse and CommitMessage.
-  optional ExtendedAttributes extended_attributes = 17;
+  // Deprecated.
+  // optional ExtendedAttributes extended_attributes = 17;
 
   // If true, indicates that this item has been (or should be) deleted.
   // Present in both GetUpdatesResponse and CommitMessage.
   optional bool deleted = 18 [default = false];
 
   // A GUID that identifies the the sync client who initially committed
   // this entity.  This value corresponds to |cache_guid| in CommitMessage.
   // This field, along with |originator_client_item_id|, can be used to
   // reunite the original with its official committed version in the case
   // where a client does not receive or process the commit response for
@@ skipping 240 matching lines @@
   // Opaque store ID; if it changes, the contents of the client's cache
   // is meaningless to this server.  This happens most typically when
   // you switch from one storage backend instance (say, a test instance)
   // to another (say, the official instance).
   optional string store_birthday = 6;
 
   optional ClientCommand client_command = 7;
   optional ProfilingData profiling_data = 8;
 };