Add key_idle_power_cases for ensuring idle activity on Android

tools/perf/page_sets/android_screen_restoration_shared_state.py

Index: tools/perf/page_sets/android_screen_restoration_shared_state.py
diff --git a/tools/perf/page_sets/android_screen_restoration_shared_state.py b/tools/perf/page_sets/android_screen_restoration_shared_state.py
new file mode 100644
index 0000000000000000000000000000000000000000..c08af94f089634f98bb8b2658b1151284ef6ccc7
--- /dev/null
+++ b/tools/perf/page_sets/android_screen_restoration_shared_state.py
@@ -0,0 +1,22 @@
+# 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.page import shared_page_state
+
+
+class AndroidScreenRestorationSharedState(shared_page_state.SharedPageState):
+  """ Ensures the screen is on before and after each user story run. """
+
+  def WillRunUserStory(self, page):
+    super(AndroidScreenRestorationSharedState, self).WillRunUserStory(page)
+    self._EnsureScreenOn()
+
+  def DidRunUserStory(self, results):
+    try:
+      super(AndroidScreenRestorationSharedState, self).DidRunUserStory(results)
+    finally:
+      self._EnsureScreenOn()
+
+  def _EnsureScreenOn(self):
+    self.platform.android_action_runner.TurnScreenOn()
+