[Telemetry] Remove page_test.DidRunTest hook.

tools/perf/benchmarks/dom_perf.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.
 
 import json
 import math
 import os
 
 from telemetry import benchmark
 from telemetry.core import util
@@ skipping 21 matching lines @@
   mean = math.pow(math.e, (log_sum / len(new_values)))
   # Return the rounded mean.
   return int(round(mean))
 
 
 SCORE_UNIT = 'score (bigger is better)'
 SCORE_TRACE_NAME = 'score'
 
 
 class _DomPerfMeasurement(page_test.PageTest):
-  def __init__(self):
+  def __init__(self, expected_num_runs):
     super(_DomPerfMeasurement, self).__init__()
+    self._expected_num_runs = expected_num_runs
+    self._runs_count = 0
 
   def ValidateAndMeasurePage(self, page, tab, results):
     try:
       def _IsDone():
         return tab.GetCookieByName('__domperf_finished') == '1'
       util.WaitFor(_IsDone, 600)
 
       data = json.loads(tab.EvaluateJavaScript('__domperf_result'))
       for suite in data['BenchmarkSuites']:
         # Skip benchmarks that we didn't actually run this time around.
         if len(suite['Benchmarks']) or suite['score']:
           results.AddValue(scalar.ScalarValue(
               results.current_page, '%s.%s' % (suite['name'], SCORE_TRACE_NAME),
               SCORE_UNIT, suite['score'], important=False))
+
     finally:
       tab.EvaluateJavaScript('document.cookie = "__domperf_finished=0"')
+    self._runs_count += 1
+    # Only compute total metric when we reach the number of expected run.
+    if self._runs_count == self._expected_num_runs:
+      self._ComputeTotalMetric(results)
 
-  def DidRunTest(self, browser, results):
+  def _ComputeTotalMetric(self, results):
     # Now give the geometric mean as the total for the combined runs.
     combined = merge_values.MergeLikeValuesFromDifferentPages(
         results.all_page_specific_values,
         group_by_name_suffix=True)
     combined_score = [x for x in combined if x.name == SCORE_TRACE_NAME][0]
     total = _GeometricMean(combined_score.values)
     results.AddSummaryValue(
         scalar.ScalarValue(None, 'Total.' + SCORE_TRACE_NAME, SCORE_UNIT,
                            total))
 
 
 @benchmark.Disabled('android', 'linux')  # http://crbug.com/458540
 class DomPerf(benchmark.Benchmark):
   """A suite of JavaScript benchmarks for exercising the browser's DOM.
 
   The final score is computed as the geometric mean of the individual results.
   Scores are not comparable across benchmark suite versions and higher scores
   means better performance: Bigger is better!"""
-  test = _DomPerfMeasurement
+
+  RUN_PARAMS = [
+    'Accessors',
+    'CloneNodes',
+    'CreateNodes',
+    'DOMDivWalk',
+    'DOMTable',
+    'DOMWalk',
+    'Events',
+    'Get+Elements',
+    'GridSort',
+    'Template'
+  ]
 
   @classmethod
   def Name(cls):
     return 'dom_perf'
 
+  def CreatePageTest(self, options):
+    del options
+    return _DomPerfMeasurement(len(self.RUN_PARAMS))
+
   def CreatePageSet(self, options):
     dom_perf_dir = os.path.join(util.GetChromiumSrcDir(), 'data', 'dom_perf')
-    run_params = [
-      'Accessors',
-      'CloneNodes',
-      'CreateNodes',
-      'DOMDivWalk',
-      'DOMTable',
-      'DOMWalk',
-      'Events',
-      'Get+Elements',
-      'GridSort',
-      'Template'
-    ]
     ps = page_set.PageSet(file_path=dom_perf_dir)
-    for param in run_params:
+    for param in self.RUN_PARAMS:
       ps.AddUserStory(page_module.Page(
           'file://run.html?reportInJS=1&run=%s' % param, ps, ps.base_dir))
     return ps