[WEEX-264] resolve the crash of waterfall component due to the unstable layout engine, got the nan sometimes from the same input css, protect here for the crash stack see more here https://issues.apache.org/jira/browse/WEEX-264
Bug:264 [ Full content available at: https://github.com/apache/incubator-weex/pull/1501 ] This message was relayed via gitbox.apache.org for [email protected]
