Add benchmark that imitates news reading.

tools/perf/page_sets/system_health/browsing_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.
+
+import sys
+
+from page_sets.system_health import platforms
+from page_sets.system_health import system_health_story
+
+from telemetry import story
+
+
+class _BrowsingStory(system_health_story.SystemHealthStory):
+  """Abstract base class for browsing stories.
+
+  A browsing story visits items on the main page. Subclasses provide
+  CSS selector to identify the items and implement interaction using
+  the helper methods of this class.
+  """
+
+  IS_SINGLE_PAGE_APP = False
+  ITEM_SELECTOR = NotImplemented

[petrcermak, 2016/07/12 12:53:19]

Sorry to keep changing my mind. Now that I look at this, it seems strange that
_BrowsingStory has knowledge of items (given that iteration over items actually
happens inside _NewsBrowsingStory). Therefore, I suggest you move ITEM_SELECTOR
and ITEM_TO_VISIT to _NewsBrowsingStory. In addition, please change
_NavigateToItem to (but keep it inside _BrowsingStory):

def _ClickLink(self, action_runner, element_function):
  action_runner.WaitForElement(element_function)
  ...

The query selector logic should be in _NewsBrowsingStory:

def _NavigateToItem(self, action_runner, index):
  item_selector = ...
  return self._ClickLink(action_runner, element_function=item_selector)

[ulan, 2016/07/12 14:05:47]

I extracted _ClinkLink.

Item related code in _BrowsingStory will be useful later when we add media
browsing stories. They also navigate to items, but do not use the back button.

[petrcermak, 2016/07/12 15:30:54]

I see. In that case I'm fine either way (extracted or not extracted).

[ulan, 2016/07/12 17:14:48]

Acknowledged.

+  ITEMS_TO_VISIT = 4
+
+  def __init__(self, story_set):
+    super(_BrowsingStory, self).__init__(
+        story_set, take_memory_measurement=False)
+
+  def _WaitForNavigation(self, action_runner):
+    if not self.IS_SINGLE_PAGE_APP:
+      action_runner.WaitForNavigate()
+
+  def _NavigateToItem(self, action_runner, index):
+    item_selector = 'document.querySelectorAll("%s")[%d]' % (
+        self.ITEM_SELECTOR, index)
+    action_runner.WaitForElement(element_function=item_selector)
+    action_runner.ClickElement(element_function=item_selector)
+    self._WaitForNavigation(action_runner)
+
+  def _NavigateBack(self, action_runner):
+    action_runner.ExecuteJavaScript('window.history.back()')
+    self._WaitForNavigation(action_runner)
+
+
+class _NewsBrowsingStory(_BrowsingStory):
+  """Abstract base class for news user stories.
+
+  A news story imitates browsing a news website:
+  1. Load the main page.
+  2. Open and scroll the first news item.
+  3. Go back to the main page and scroll it.
+  4. Open and scroll the second news item.
+  5. Go back to the main page and scroll it.
+  6. etc.
+  """
+
+  ITEM_READ_TIME_IN_SECONDS = 3
+  ITEM_SCROLL_REPEAT = 2
+  MAIN_PAGE_SCROLL_REPEAT = 0
+
+  def _DidLoadDocument(self, action_runner):
+    for i in xrange(self.ITEMS_TO_VISIT):
+      self._NavigateToItem(action_runner, i)
+      self._ReadNewsItem(action_runner)
+      self._NavigateBack(action_runner)
+      self._ScrollMainPage(action_runner)
+
+  def _ReadNewsItem(self, action_runner):
+    action_runner.tab.WaitForDocumentReadyStateToBeComplete()
+    action_runner.Wait(self.ITEM_READ_TIME_IN_SECONDS)
+    action_runner.RepeatableBrowserDrivenScroll(
+        repeat_count=self.ITEM_SCROLL_REPEAT)
+
+  def _ScrollMainPage(self, action_runner):
+    action_runner.tab.WaitForDocumentReadyStateToBeComplete()
+    action_runner.RepeatableBrowserDrivenScroll(
+        repeat_count=self.MAIN_PAGE_SCROLL_REPEAT)
+
+
+##############################################################################
+# News browsing stories.
+##############################################################################
+
+
+class RedditDesktopStory(_NewsBrowsingStory):
+  """The top website in http://www.alexa.com/topsites/category/News"""
+  NAME = 'browse:news:reddit'
+  URL = 'https://www.reddit.com/top/?sort=top&t=week'
+  SUPPORTED_PLATFORMS = platforms.DESKTOP_ONLY
+  ITEM_SELECTOR = '.thing .title > a'
+
+
+class RedditMobileStory(_NewsBrowsingStory):
+  """The top website in http://www.alexa.com/topsites/category/News"""
+  NAME = 'browse:news:reddit'
+  URL = 'https://m.reddit.com/?sort=top&time=week'
+  SUPPORTED_PLATFORMS = platforms.MOBILE_ONLY
+  ITEM_SELECTOR = '.PostHeader__post-title-line'
+  IS_SINGLE_PAGE_APP = True
+
+
+class CnnStory(_NewsBrowsingStory):
+  """The second top website in http://www.alexa.com/topsites/category/News"""
+  NAME = 'browse:news:cnn'
+  URL = 'http://edition.cnn.com/'
+  ITEM_SELECTOR = '.cd__content > h3 > a'
+  # TODO(ulan): Enable this story on mobile once it uses less memory and
+  # does not crash with OOM.
+  SUPPORTED_PLATFORMS = platforms.DESKTOP_ONLY
+
+
+class NytimesMobileStory(_NewsBrowsingStory):
+  """The third top website in http://www.alexa.com/topsites/category/News"""
+  NAME = 'browse:news:nytimes'
+  URL = 'http://mobile.nytimes.com'
+  SUPPORTED_PLATFORMS = platforms.MOBILE_ONLY
+  ITEM_SELECTOR = '.sfgAsset-link'
+  # Visiting more items causes OOM.
+  ITEMS_TO_VISIT = 2
+
+
+class NytimesDesktopStory(_NewsBrowsingStory):
+  """The third top website in http://www.alexa.com/topsites/category/News"""
+  NAME = 'browse:news:nytimes'
+  URL = 'http://www.nytimes.com'
+  SUPPORTED_PLATFORMS = platforms.DESKTOP_ONLY
+  ITEM_SELECTOR = '.story-heading > a'
+
+
+class HackerNewsStory(_NewsBrowsingStory):
+  NAME = 'browse:news:hackernews'
+  URL = 'https://news.ycombinator.com'
+  ITEM_SELECTOR = '.athing .title > a'
+
+
+# Facebook on desktop is not interesting because it embeds post comments
+# directly in the main timeline.
+class FacebookMobileStory(_NewsBrowsingStory):
+  NAME = 'browse:social:facebook'
+  URL = 'https://facebook.com/natgeo'
+  ITEM_SELECTOR = 'article ._5msj'
+  SUPPORTED_PLATFORMS = platforms.MOBILE_ONLY
+
+
+class TwitterMobileStory(_NewsBrowsingStory):
+  NAME = 'browse:social:twitter'
+  URL = 'https://mobile.twitter.com/cnnbrk'
+  ITEM_SELECTOR = '.Tweet-text'
+  SUPPORTED_PLATFORMS = platforms.MOBILE_ONLY
+
+
+class TwitterDesktopStory(_NewsBrowsingStory):
+  NAME = 'browse:social:twitter'
+  URL = 'https://twitter.com/cnnbrk'
+  ITEM_SELECTOR = '.tweet-text'
+  SUPPORTED_PLATFORMS = platforms.DESKTOP_ONLY
+  IS_SINGLE_PAGE_APP = True
+
+
+class WashingtonPostMobileStory(_NewsBrowsingStory):
+  """Progressive website"""
+  NAME = 'browse:news:washingtonpost'
+  URL = 'https://www.washingtonpost.com/pwa'
+  SUPPORTED_PLATFORMS = platforms.MOBILE_ONLY
+  ITEM_SELECTOR = '.hed > a'
+  IS_SINGLE_PAGE_APP = True
+
+  def _DidLoadDocument(self, action_runner):
+    # Close the popup window.
+    action_runner.ClickElement(selector='.close')
+    self._DidLoadDocument(action_runner)
+
+
+class QqMobileStory(_NewsBrowsingStory):
+  NAME = 'browse:news:qq'
+  URL = 'http://news.qq.com'
+  # qq.com on desktop opens a news item in a separate tab, for which the back
+  # button does not work.
+  SUPPORTED_PLATFORMS = platforms.MOBILE_ONLY
+  ITEM_SELECTOR = '.list .full a'
+
+
+##############################################################################
+# Browsing story sets.
+##############################################################################
+
+
+def _IterAllNewsBrowsingStoryClasses():
+  return system_health_story.IterAllStoryClasses(
+      sys.modules[__name__], _NewsBrowsingStory)
+
+
+class _NewsBrowsingStorySet(story.StorySet):
+  PLATFORM = NotImplemented
+
+  def __init__(self):
+    super(_NewsBrowsingStorySet, self).__init__(
+        archive_data_file=('../data/news_%s.json' % self.PLATFORM),
+        cloud_storage_bucket=story.PARTNER_BUCKET)
+    for story_class in _IterAllNewsBrowsingStoryClasses():
+      if self.PLATFORM not in story_class.SUPPORTED_PLATFORMS:
+        continue
+      self.AddStory(story_class(self))
+
+
+class DesktopNewsStorySet(_NewsBrowsingStorySet):
+  PLATFORM = platforms.DESKTOP
+
+
+class MobileNewsStorySet(_NewsBrowsingStorySet):
+  PLATFORM = platforms.MOBILE