Backed out changeset b2fe8f4df701 (bug 1158387) for making Win64 xpcshell nearly permafail.

netwerk/cookie/nsCookieService.cpp

@@ -1474,6 +1474,10 @@ nsCookieService::TryInitDB(bool aRecreateDB)
     }
   }
 
+  // make operations on the table asynchronous, for performance
+  mDefaultDBState->dbConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
+    "PRAGMA synchronous = OFF"));
+
   // Use write-ahead-logging for performance. We cap the autocheckpoint limit at
   // 16 pages (around 500KB).
   mDefaultDBState->dbConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(