Add unique hashing to sync API.

chrome/browser/sync/syncable/syncable.cc

 // 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.
 
 #include "chrome/browser/sync/syncable/syncable.h"
 
 #include "build/build_config.h"
 
 #include <sys/stat.h>
 #if defined(OS_POSIX)
@@ skipping 1057 matching lines @@
   if (Get(SPECIFICS).HasExtension(sync_pb::preference))
     return PREFERENCES;
   if (Get(SPECIFICS).HasExtension(sync_pb::autofill))
     return AUTOFILL;
   if (IsRoot())
     return TOP_LEVEL_FOLDER;
   // Loose check for server-created top-level folders that aren't
   // bound to a particular model type.
   if (!Get(UNIQUE_SERVER_TAG).empty() && Get(IS_DIR))
     return TOP_LEVEL_FOLDER;
 

[ncarter (slow), 2010/02/18 01:05:40]

It's probably okay for these DCHECKs to die -- but they did find a whole bunch
of unit test bugs while they were around.  They might still be appropriate in
the wtrans dtor, but I'm not insisting.

[chron, 2010/02/18 01:09:32]

These dchecks weren't really valid since we call GetModelType in different
places now. One such case is if we call it on a local item that we haven't
stuffed any data into, it interferes with the other assert that I think is more
useful. Can't "assert not set" if this is the case. 

-  // Otherwise, we don't have a local type yet.  That should only happen
-  // if the item doesn't exist locally -- like if it's a new update item.
-  // It's possible we'll need to relax these checks in the future; they're
-  // just here for now as a safety measure.
-  DCHECK(Get(ID).ServerKnows());
-  DCHECK(Get(IS_UNAPPLIED_UPDATE));
-  DCHECK(!Get(IS_UNSYNCED));
-  DCHECK(Get(BASE_VERSION) == CHANGES_VERSION);
-  DCHECK(Get(IS_DEL));
   return UNSPECIFIED;
 }
 
 ///////////////////////////////////////////////////////////////////////////
 // MutableEntry
 
 MutableEntry::MutableEntry(WriteTransaction* trans, Create,
                            const Id& parent_id, const string& name)
     : Entry(trans),
       write_transaction_(trans) {
@@ skipping 460 matching lines @@
   return s << std::dec;
 }
 
 FastDump& operator<<(FastDump& dump, const syncable::Blob& blob) {
   if (blob.empty())
     return dump;
   string buffer(HexEncode(&blob[0], blob.size()));
   dump.out_->sputn(buffer.c_str(), buffer.size());
   return dump;
 }