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

tools/telemetry/telemetry/web_perf/metrics/startup.py

Index: tools/telemetry/telemetry/web_perf/metrics/startup.py
diff --git a/tools/telemetry/telemetry/web_perf/metrics/startup.py b/tools/telemetry/telemetry/web_perf/metrics/startup.py
new file mode 100644
index 0000000000000000000000000000000000000000..18025dfc01fca69e4c6b4af9fc0b816685821105
--- /dev/null
+++ b/tools/telemetry/telemetry/web_perf/metrics/startup.py
@@ -0,0 +1,95 @@
+# 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.
+
+from telemetry import value
+from telemetry.web_perf.metrics import timeline_based_metric
+
+_PROCESS_CREATION = 'Startup.BrowserProcessCreation'
+_MAIN_ENTRY_POINT = 'Startup.BrowserMainEntryPoint'
+
+# A dictionary that maps metric names to a value, which can be either of
+# the two:
+#  1. A tuple of one event name if the event itself contains reported duration
+#  2. A tuple of two event names if the value to report is the time difference
+#     between starting these events
+_METRICS = {
+  'messageloop_start_time':
+      ('Startup.BrowserMessageLoopStartTimeFromMainEntry',),
+
+  'window_display_time':
+      ('Startup.BrowserWindowDisplay',),
+
+  'open_tabs_time':
+      ('Startup.BrowserOpenTabs',),
+
+  'first_non_empty_paint_time':
+      ('Startup.FirstWebContents.NonEmptyPaint2',),
+
+  'first_main_frame_load_time':
+      ('Startup.FirstWebContents.MainFrameLoad2',),
+
+  'foreground_tab_load_complete':
+      (_MAIN_ENTRY_POINT, 'loadEventEnd'),
+
+  # TODO(gabadie): Implement foreground_tab_request_start between
+  # _MAIN_ENTRY_POINT and 'requestStart' once crbug.com/552472 fixed.
+}
+
+_TRACKED_EVENT_NAMES = set()
+for i in _METRICS.values():
+  _TRACKED_EVENT_NAMES.add(i[0])
+  if len(i) == 2:
+    _TRACKED_EVENT_NAMES.add(i[1])
+
+
+class StartupTimelineMetric(timeline_based_metric.TimelineBasedMetric):
+  """Reports summary stats from important startup events."""
+
+  def __init__(self):
+    super(StartupTimelineMetric, self).__init__()
+
+  def AddResults(self, model, _renderer_thread, interactions, results):
+    pass
+
+  def AddWholeTraceResults(self, model, results):
+    browser = model.browser_process
+
+    if not browser:
+      return
+
+    # Produce a map of events to track.
+    tracked_events = {}
+    for event in browser.parent.IterAllEvents(
+      event_predicate=lambda event: event.name in _TRACKED_EVENT_NAMES):
+      # In case of a begin/end trace event, only track the begin that contain
+      # the duration.
+      if event.name in tracked_events:
+        continue
+
+      tracked_events[event.name] = event
+
+    # Generate the metric values according to the tracked events.
+    for display_name, event_names in _METRICS.iteritems():
+      if event_names[0] not in tracked_events:
+        continue
+
+      duration = None
+      if len(event_names) == 1:
+        # The single event contains the duration to report.
+        duration = tracked_events[event_names[0]].duration
+
+      elif len(event_names) == 2:
+        # The duration is defined as the difference between two event starts.
+        if event_names[1] not in tracked_events:
+          continue
+
+        duration = (tracked_events[event_names[1]].start -
+            tracked_events[event_names[0]].start)
+
+      results.AddValue(value.scalar.ScalarValue(
+        page=results.current_page,
+        name=display_name,
+        units='ms',
+        value=duration,
+        improvement_direction=value.improvement_direction.DOWN))