Add --options to nanobench, similar to --key but for non-identifying options.

Add --options to nanobench, similar to --key but for non-identifying options.

Friends with https://codereview.chromium.org/487233003/

Example of out/Release/nanobench --options build_number 12374 --match patch_grid_texs_small

{
   "gitHash":"unknown-revision",
   "options":{
      "build_number":"12374",
      "system":"UNIX"
   },
   "results":{
      "patch_grid_texs_small_640_480":{
         "565":{
            "max_ms":0.268116,
            "mean_ms":0.2318529,
            "median_ms":0.235337,
            "min_ms":0.219158,
            "options":{
               "source_type":"bench"
            },
            "stddev_ms":0.01491263917658814
         },
         "8888":{
            "max_ms":0.231881,
            "mean_ms":0.2214668,
            "median_ms":0.219356,
            "min_ms":0.218887,
            "options":{
               "source_type":"bench"
            },
            "stddev_ms":0.004595541070791701
         },
         "gpu":{
            "max_ms":0.1398304782608696,
            "mean_ms":0.128833402173913,
            "median_ms":0.1316798695652174,
            "min_ms":0.1111915434782609,
            "options":{
               "GL_RENDERER":"Quadro 600/PCIe/SSE2",
               "GL_SHADING_LANGUAGE_VERSION":"4.40 NVIDIA via Cg compiler",
               "GL_VENDOR":"NVIDIA Corporation",
               "GL_VERSION":"4.4.0 NVIDIA 331.79",
               "source_type":"bench"
            },
            "stddev_ms":0.008923738937837156
         }
      }
   }
}

BUG=skia:
R=jcgregorio@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/490683002