sync: don't notify from ~BaseTransaction if the writer is INVALID.

chrome/browser/sync/syncable/syncable.h

Index: chrome/browser/sync/syncable/syncable.h
diff --git a/chrome/browser/sync/syncable/syncable.h b/chrome/browser/sync/syncable/syncable.h
index 3a673f0bf4fb9b776906f6a19d9657c943cb8b00..196fe007e194c2cd5d66927c3221229ba2ece4de 100644
--- a/chrome/browser/sync/syncable/syncable.h
+++ b/chrome/browser/sync/syncable/syncable.h
@@ -33,7 +33,6 @@
 #include "chrome/browser/sync/syncable/directory_event.h"
 #include "chrome/browser/sync/syncable/syncable_id.h"
 #include "chrome/browser/sync/syncable/model_type.h"
-#include "chrome/browser/sync/util/dbgq.h"
 #include "chrome/browser/sync/util/immutable.h"
 #include "chrome/browser/sync/util/time.h"
 
@@ -1129,10 +1128,6 @@ class Directory {
     // The next metahandle is protected by kernel mutex.
     int64 next_metahandle;
 
-    // Keep a history of recently flushed metahandles for debugging
-    // purposes.  Protected by the save_changes_mutex.
-    DebugQueue<int64, 1000> flushed_metahandles;
-
     // The delegate for directory change events.  Can be NULL.
     DirectoryChangeDelegate* const delegate;