Telemetry: Quiescent power benchmarks for Mac

tools/perf/measurements/energy.py

+# 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 time
+
+from metrics import cpu
+from metrics import power
+from telemetry.page import page_test
+
+
+class Energy(page_test.PageTest):
+  """Measures power usage, idle wakeups, and CPU utilization."""
+
+  # Amount of time to measure, in seconds.
+  SAMPLE_TIME = 10
+
+  def ValidateAndMeasurePage(self, page, tab, results):
+    metrics = [ power.PowerMetric(tab.browser.platform), cpu.CpuMetric(tab.browser) ]

[ccameron, 2015/04/20 21:36:33]

It may be a good idea to wait for a few seconds here, just to ensure that things
are "really" quiescent. Might be worth figuring out what that level is
empirically on some machine.

[Andre, 2015/04/20 21:52:40]

metric.PowerMetric supports measuring quiescent power draw by passing a duration
parameter to the constructor (measurements.TabSwitching does this).

[Andre, 2015/04/22 00:46:54]

I've added util.WaitFor(tab.hasReachedQuiescence) call here.

+    for metric in metrics:
+      metric.Start(page, tab)
+
+    time.sleep(Energy.SAMPLE_TIME)
+
+    for metric in metrics:
+      metric.Stop(page, tab)
+      metric.AddResults(tab, results)