Add key_idle_power_cases for ensuring idle activity on Android

tools/perf/page_sets/key_power_cases.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.
+from telemetry.page import page as page_module
+from telemetry.page import page_set as page_set_module
+
+class KeyPowerPage(page_module.Page):
+
+  def __init__(self, url, page_set, turn_screen_off):
+    super(KeyPowerPage, self).__init__(
+        url=url, page_set=page_set)
+    self.user_agent_type = 'mobile'
+    self._turn_screen_off = turn_screen_off
+
+  def RunNavigateSteps(self, action_runner):
+    action_runner._tab.browser.platform.android_action_runner.TurnScreenOn()
+    super(KeyPowerPage, self).RunNavigateSteps(action_runner)
+    action_runner.Wait(2)
+    if self._turn_screen_off:
+      action_runner._tab.browser.platform.android_action_runner.TurnScreenOff()
+      action_runner.Wait(2)
+
+  def RunPageInteractions(self, action_runner):
+    action_runner.Wait(20)
+
+
+class KeyPowerCasesPageSet(page_set_module.PageSet):
+
+  """ Key power cases """
+
+  def __init__(self):
+    super(KeyPowerCasesPageSet, self).__init__(
+      user_agent_type='mobile')
+
+    foreground_urls_list = [
+      # Why: Ensure minimal activity for static, empty pages in the foreground.
+      'file://key_power_cases/blank.html',
+    ]
+
+    for url in foreground_urls_list:
+      self.AddUserStory(KeyPowerPage(url, self, False))
+
+    background_urls_list = [
+      # Why: Ensure animated GIFs aren't processed when Chrome is backgrounded.
+      'file://key_power_cases/animated-gif.html',
+      # Why: Ensure CSS animations aren't processed when Chrome is backgrounded.
+      'file://key_power_cases/css-animation.html',
+      # Why: Ensure rAF is suppressed when Chrome is backgrounded.
+      'file://key_power_cases/request-animation-frame.html',
+      # Why: Ensure setTimeout is throttled when Chrome is backgrounded.
+      'file://key_power_cases/set-timeout.html',
+    ]
+
+    for url in background_urls_list:
+      self.AddUserStory(KeyPowerPage(url, self, True))