Merge all logic in PageMeasurementResults to PageTestResults.

tools/telemetry/telemetry/web_perf/metrics/fast_metric_unittest.py

 # Copyright 2014 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 logging
 import StringIO
 import unittest
 
 from telemetry.web_perf.metrics import fast_metric
 from telemetry.timeline import model as model_module
@@ skipping 24 matching lines @@
         **kwargs))
 
   def MeasureFakePage(self, metric):
     self._renderer_thread.async_slices.extend(self._async_slices)
     self._model.FinalizeImport()
     interaction_records = [
         tir_module.TimelineInteractionRecord.FromAsyncEvent(s)
         for s in self._async_slices]
     results = page_measurement_results.PageMeasurementResults()
     fake_page = None
-    results.WillMeasurePage(fake_page)
+    results.StartTest(fake_page)
     metric.AddResults(self._model, self._renderer_thread, interaction_records,
                       results)
+    results.StopTest(fake_page)
     return results
 
 
 class FastMetricTests(unittest.TestCase):
 
   def setUp(self):
     self.log_output = StringIO.StringIO()
     self.stream_handler = logging.StreamHandler(self.log_output)
     logging.getLogger().addHandler(self.stream_handler)
 
@@ skipping 74 matching lines @@
     metric = fast_metric.FastMetric()
     results = renderer_thread_helper.MeasureFakePage(metric)
 
     expected_values = [
         ('fast-cpu_time', 'ms', 44),  # thread overlap
         ('fast-duration', 'ms', 54),  # 27 + 27; total interaction wall duration
         ('fast-idle_time', 'ms', 18),  # 27 - ((2 + 45) - 45); interaction wall
                                        # time outside of renderer wall time.
         ]
     self.assertEqual(expected_values, self.ActualValues(results))