Add System health stories for Emerging market

tools/perf/page_sets/system_health/blank_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 page_sets.system_health import system_health_story
+from page_sets.system_health import platforms
 
 
 class BlankAboutBlankStory(system_health_story.SystemHealthStory):
   """Story that loads the about:blank page."""
 
   NAME = 'blank:about:blank'
   URL = 'about:blank'
 
   def _DidLoadDocument(self, action_runner):
     # Request a RAF and wait for it to be processed to ensure that the metric
     # Startup.FirstWebContents.NonEmptyPaint2 is recorded.
     action_runner.ExecuteJavaScript(
         """
         window.__hasRunRAF = false;
         requestAnimationFrame(function() {
           window.__hasRunRAF = true;
         });
         """
     )
     action_runner.WaitForJavaScriptCondition("window.__hasRunRAF")
+
+
+class MobileNewTabPageStory(system_health_story.SystemHealthStory):
+  """Story that loads new tab page and opens menu."""
+
+  NAME = 'blank:about:newtab'

[perezju, 2017/03/31 08:45:54]

I don't think this is a "blank" story, it's actually hopping for content to get
loaded.

Maybe this could be browse:chrome:newtab?

[ssid, 2017/04/04 03:43:48]

Done.

+  URL = 'chrome://newtab'
+
+  def RunPageInteractions(self, action_runner):
+    package = action_runner.tab.browser.GetBrowserInfo().package_name
+    platform = action_runner.tab.browser.platform
+    menu_button = package+':id/menu_button'
+    platform.system_ui.WaitForUiNode(resource_id=menu_button)
+    menu_button = platform.system_ui.GetUiNode(resource_id=menu_button)
+    menu_button.Tap()
+    platform.system_ui.WaitForUiNode(resource_id=package+':id/menu_item_text')
+
+  SUPPORTED_PLATFORMS = platforms.MOBILE_ONLY