Added upload script for using Rietveld code review tool.
Added upload script for using Rietveld code review tool.

YanjieGao/sparrow,YanjieGao/sparrow,radlab/sparrow,dmwu/sparrow,radlab/sparrow,dmwu/sparrow,dmwu/sparrow,radlab/sparrow,radlab/sparrow,dmwu/sparrow,YanjieGao/sparrow