Modify list_system_health_stories to generate_system_health_csv

tools/perf/page_sets/system_health/system_health_story.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 platforms
 from page_sets.system_health import story_tags
 
 from telemetry import decorators
 from telemetry.page import page
 from telemetry.page import shared_page_state
@@ skipping 69 matching lines @@
         tags.append(t.name)
     super(SystemHealthStory, self).__init__(
         shared_page_state_class=_SystemHealthSharedState, page_set=story_set,
         name=self.NAME, url=self.URL, tags=tags,
         credentials_path='../data/credentials.json',
         grouping_keys={'case': case, 'group': group},
         platform_specific=self.PLATFORM_SPECIFIC)
     self._take_memory_measurement = take_memory_measurement
 
   @classmethod
+  def GetStoryDescription(cls):
+    if cls.__doc__:
+      return cls.__doc__
+    return cls.GenerateStoryDescription()
+
+  @classmethod
+  def GenerateStoryDescription(cls):
+    """ Subclasses of SystemHealthStory can override this to auto generate
+    their story description.
+    However, it's recommended to use the Python docstring to describe the user
+    stories instead and this should only be used for very repetitive cases.
+    """
+    return None
+
+  @classmethod
   def CanRun(cls, possible_browser):
     if (decorators.ShouldSkip(cls, possible_browser)[0] or
         cls.ShouldDisable(possible_browser)):
       return False
     return True
 
   @classmethod
   def ShouldDisable(cls, possible_browser):
     """Override this method to disable a story under specific conditions.
 
@@ skipping 15 matching lines @@
     pass
 
   def RunNavigateSteps(self, action_runner):
     self._Login(action_runner)
     super(SystemHealthStory, self).RunNavigateSteps(action_runner)
 
   def RunPageInteractions(self, action_runner):
     action_runner.tab.WaitForDocumentReadyStateToBeComplete()
     self._DidLoadDocument(action_runner)
     self._Measure(action_runner)