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

tools/perf/benchmarks/octane.py

 # Copyright (c) 2012 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 os
 
 from telemetry import test
 from telemetry.core import util
 from telemetry.page import page_measurement
 from telemetry.page import page_set
 
 
-class OctaneMeasurement(page_measurement.PageMeasurement):
+class _OctaneMeasurement(page_measurement.PageMeasurement):
   def MeasurePage(self, _, tab, results):
     tab.WaitForJavaScriptExpression(
         'completed && !document.getElementById("progress-bar-container")', 300)
 
     js_get_results = """
 var results = {};
 var result_divs = document.querySelectorAll('.p-result');
 for (var r in result_divs) {
   if (result_divs[r].id && result_divs[r].id.indexOf('Result-') == 0) {
     var key = result_divs[r].id.replace('Result-', '');
@@ skipping 10 matching lines @@
       if value == '...':
         continue
       data_type = 'unimportant'
       if key == 'score':
         data_type = 'default'
       results.Add(key, 'score (bigger is better)', value, data_type=data_type)
 
 
 class Octane(test.Test):
   """Google's Octane JavaScript benchmark."""
-  test = OctaneMeasurement
+  test = _OctaneMeasurement
 
   def CreatePageSet(self, options):
     octane_dir = os.path.join(util.GetChromiumSrcDir(), 'chrome', 'test',
                               'data', 'perf', 'third_party', 'octane')
     return page_set.PageSet.FromDict({
         'pages': [
           { 'url': 'file://index.html?auto=1' }
           ]
         }, octane_dir)