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

tools/perf/benchmarks/html5gaming.py

 # Copyright 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.
 
 """Impact HTML5 Gaming benchmark.
 
 Tests one very specific use case: smooth running games rendered with the
 <canvas> element. The score for the HTML5-Benchmark takes the total time the
 browser spent rendering frames (formula is 1000000/(sqrt(totalTime) + lagTime *
 0.1)). The benchmark automatically runs at a reasonable screen size. Final
 score is a indicator for the browser's ability to smoothly run HTML5 games."""
 
 import os
 
 from telemetry import test
 from telemetry.page import page_measurement
 from telemetry.page import page_set
 
 
-class HTML5GamingMeasurement(page_measurement.PageMeasurement):
+class _HTML5GamingMeasurement(page_measurement.PageMeasurement):
   def MeasurePage(self, _, tab, results):
     tab.ExecuteJavaScript('benchmark();')
     # Default value of score element is 87485, its value is updated with actual
     # score when test finish.
     tab.WaitForJavaScriptExpression(
         'document.getElementById("score").innerHTML != "87485"', 200)
     result = int(tab.EvaluateJavaScript(
         'document.getElementById("score").innerHTML'))
     results.Add('Score', 'score', result)
 
 
 class HTML5Gaming(test.Test):
   """Imapct HTML5 smooth running games benchmark suite."""
-  test = HTML5GamingMeasurement
+  test = _HTML5GamingMeasurement
   def CreatePageSet(self, options):
     return page_set.PageSet.FromDict({
         'archive_data_file': '../page_sets/data/html5gaming.json',
         'make_javascript_deterministic': False,
         'pages': [
           { 'url':
               'http://html5-benchmark.com/'}
            ]
         }, os.path.abspath(__file__))