Add unique hashing to sync API.

chrome/browser/sync/syncable/syncable.cc

Index: chrome/browser/sync/syncable/syncable.cc
diff --git a/chrome/browser/sync/syncable/syncable.cc b/chrome/browser/sync/syncable/syncable.cc
index ff0ab77479dbb17b272590aebaef86210d07727b..fb37c3a5f372942ab32538bb3781ef0256573cfa 100755
--- a/chrome/browser/sync/syncable/syncable.cc
+++ b/chrome/browser/sync/syncable/syncable.cc
@@ -1076,15 +1076,6 @@ syncable::ModelType Entry::GetModelType() const {
   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;
 }