Re-implements start_with_url.* benchmarks as start_with_url2.* using TBM

tools/telemetry/telemetry/web_perf/metrics/startup_unittest.py

Index: tools/telemetry/telemetry/web_perf/metrics/startup_unittest.py
diff --git a/tools/telemetry/telemetry/web_perf/metrics/startup_unittest.py b/tools/telemetry/telemetry/web_perf/metrics/startup_unittest.py
new file mode 100644
index 0000000000000000000000000000000000000000..9618e6fafbc3ab79465c299af3efdadfd8eaa963
--- /dev/null
+++ b/tools/telemetry/telemetry/web_perf/metrics/startup_unittest.py
@@ -0,0 +1,92 @@
+# Copyright 2015 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 unittest
+
+import telemetry.timeline.event as timeline_event
+from telemetry.testing import test_page_test_results
+from telemetry.web_perf.metrics import startup
+
+
+class StartupTimelineMetricTest(unittest.TestCase):
+
+  def setUp(self):
+    self.events = []
+
+  def AddEvent(self, event_name, start, duration=None):
+    event = timeline_event.TimelineEvent('my_category', event_name,
+                                         start, duration)
+    self.events.append(event)
+
+  # pylint: disable=W0201

[pasko, 2015/11/19 13:08:17]

please educate me why this is needed, maybe add a comment

[gabadie, 2015/11/19 16:25:25]

http://pylint-messages.wikidot.com/messages:w0201
Done.

+  def ComputeStartupMetrics(self):
+    results = test_page_test_results.TestPageTestResults(self)
+
+    # Create a mock model usable by StartupTimelineMetric.AddWholeTraceResults()

[pasko, 2015/11/19 13:08:17]

nit: period

[gabadie, 2015/11/19 16:25:26]

Done.

+    def iterate_events(event_predicate):

[pasko, 2015/11/19 13:08:17]

we name functions/methods/generators in CamelCase.

[gabadie, 2015/11/19 16:25:25]

My bad. Miss understood what eakuefner said.
Done.

+      for event in self.events:
+        if event_predicate(event):
+          yield event
+    class MockClass(object):
+      pass
+    model = MockClass()
+    model.browser_process = MockClass()
+    model.browser_process.parent = MockClass()
+    model.browser_process.parent.IterAllEvents = iterate_events
+
+    startup.StartupTimelineMetric().AddWholeTraceResults(model, results)
+    return results
+
+  def testUntrackedvents(self):
+    # Code coverage for untracked events, to make sure there is nothing wrong

[pasko, 2015/11/19 13:08:17]

we always try make sure that nothing wrong is going on. Please remove this
second part of the sentence.

[gabadie, 2015/11/19 16:25:25]

Done.

+    # going on.
+    self.AddEvent('uknown_event_0', 0)
+    self.AddEvent('uknown_event_1', 1)
+    self.ComputeStartupMetrics()
+
+  def testInstantEventsBasedValue(self):
+    # Test case with instant events to measure the duration between the first
+    # occurrences of two distinct events.
+    START0 = 7
+    START1 = 8
+    DURATION0 = 17
+    DURATION1 = 18
+
+    # Generate duplicated events to make sure we consider only the first one.
+    self.AddEvent(startup._MAIN_ENTRY_POINT, START0)
+    self.AddEvent(startup._MAIN_ENTRY_POINT, START1)
+    self.AddEvent('loadEventEnd', START0 + DURATION0)
+    self.AddEvent('loadEventEnd', START1 + DURATION1)
+
+    results = self.ComputeStartupMetrics()
+    results.AssertHasPageSpecificScalarValue('foreground_tab_load_complete',
+        'ms', DURATION0)
+
+  def testBeginEndEventsBasedValue(self):
+    # Test case to get the duration of the first occurrence of a duration event.
+    i = 1
+    for event_names in startup._METRICS.values():
+      if len(event_names) != 1:
+        continue
+
+      duration = 13 * i
+      i += 1
+
+      # Generate duplicated events to make sure we consider only the first one.

[pasko, 2015/11/19 13:08:17]

please avoid 'we'

... to make sure only the first event is considered

[gabadie, 2015/11/19 16:25:26]

Done.

+      self.AddEvent(event_names[0], 5, duration)
+      self.AddEvent(event_names[0], 6, duration + 2)
+
+    self.assertTrue(i > 1)
+
+    results = self.ComputeStartupMetrics()
+
+    i = 1
+    for display_name, event_names in startup._METRICS.iteritems():
+      if len(event_names) != 1:
+        continue
+
+      duration = 13 * i
+      i += 1
+
+      results.AssertHasPageSpecificScalarValue(display_name, 'ms', duration)