Add a new benchmark for cpu power measurements on steady state sites.

tools/perf/page_sets/idle_after_loading_stories.py

+# Copyright 2016 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 import story
+
+
+class IdleAfterLoadingStories(story.StorySet):
+  """Historically, Chrome has high CPU usage on these sites after the page has
+  loaded. These user stories let Chrome idle on the page."""
+
+  def __init__(self):
+    super(IdleAfterLoadingStories, self).__init__(
+        archive_data_file='data/idle_after_loading_stories.json',
+        cloud_storage_bucket=story.PARTNER_BUCKET)
+
+    # Chrome has high idle CPU usage on this site, even after its quiesced.
+    # https://crbug.com/638365.
+    self.AddStory(page_module.Page(
+        'http://www.labradortraininghq.com/labrador-training/how-to-crate-train'
+        '-a-puppy/#How_Long_DoesIt_Take_To_Crate_Train_A_Puppy', page_set=self))