[telemetry] Make single-benchmark measurements protected and undiscoverable.

tools/perf/benchmarks/sunspider.py

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 import collections
 import json
 import os
 
 from telemetry import test
 from telemetry.core import util
 from telemetry.page import page_measurement
 from telemetry.page import page_set
 
 
-class SunspiderMeasurement(page_measurement.PageMeasurement):
+class _SunspiderMeasurement(page_measurement.PageMeasurement):
   def MeasurePage(self, _, tab, results):
     tab.WaitForJavaScriptExpression(
         'window.location.pathname.indexOf("results.html") >= 0'
         '&& typeof(output) != "undefined"', 300)
 
     js_get_results = 'JSON.stringify(output);'
     js_results = json.loads(tab.EvaluateJavaScript(js_get_results))
     r = collections.defaultdict(list)
     totals = []
     # js_results is: [{'foo': v1, 'bar': v2},
     #                 {'foo': v3, 'bar': v4},
     #                 ...]
     for result in js_results:
       total = 0
       for key, value in result.iteritems():
         r[key].append(value)
         total += value
       totals.append(total)
     for key, values in r.iteritems():
       results.Add(key, 'ms', values, data_type='unimportant')
     results.Add('Total', 'ms', totals)
 
 
 class Sunspider(test.Test):
   """Apple's SunSpider JavaScript benchmark."""
-  test = SunspiderMeasurement
+  test = _SunspiderMeasurement
 
   def CreatePageSet(self, options):
     sunspider_dir = os.path.join(util.GetChromiumSrcDir(),
                                  'chrome', 'test', 'data', 'sunspider')
     return page_set.PageSet.FromDict(
         {
           'serving_dirs': ['.'],
           'pages': [{ 'url': 'file://sunspider-1.0/driver.html' }],
         },
         sunspider_dir)