Cull autofill entries older than 60 days.

chrome/browser/webdata/autocomplete_syncable_service.h

Index: chrome/browser/webdata/autocomplete_syncable_service.h
diff --git a/chrome/browser/webdata/autocomplete_syncable_service.h b/chrome/browser/webdata/autocomplete_syncable_service.h
index 963a1ad6e1fe1f6e08da4bf29f21918ee4444d4a..7dd82ba6dd09829ea209680210c4151ce3213cfd 100644
--- a/chrome/browser/webdata/autocomplete_syncable_service.h
+++ b/chrome/browser/webdata/autocomplete_syncable_service.h
@@ -6,6 +6,7 @@
 #pragma once
 
 #include <map>
+#include <set>
 #include <string>
 #include <utility>
 #include <vector>
@@ -118,6 +119,9 @@ class AutocompleteSyncableService
     sync_processor_.reset(sync_processor);
   }
 
+  // Ignore deletions of the following keys as they were never synced.
+  std::set<AutofillKey> keys_to_ignore_;
+
   // Lifetime of AutocompleteSyncableService object is shorter than
   // |web_data_service_| passed to it.
   WebDataService* web_data_service_;