[system-health] Unify SH stories interface

tools/perf/benchmarks/v8_browsing.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 re
 
 from core import perf_benchmark
 from telemetry.timeline import chrome_trace_config
 from telemetry.timeline import chrome_trace_category_filter
 from telemetry.web_perf import timeline_based_measurement
@@ skipping 40 matching lines @@
         chrome_trace_category_filter.ChromeTraceCategoryFilter(
             ','.join(categories)))
     options.config.enable_android_graphics_memtrack = True
     # Trigger periodic light memory dumps every 1000 ms.
     memory_dump_config = chrome_trace_config.MemoryDumpConfig()
     memory_dump_config.AddTrigger('light', 1000)
     options.config.chrome_trace_config.SetMemoryDumpConfig(memory_dump_config)
     options.SetTimelineBasedMetrics(['v8AndMemoryMetrics'])
     return options
 
+  def CreateStorySet(self, options):
+    return page_sets.SystemHealthStorySet(platform=self.PLATFORM, case='browse')
+
   @classmethod
   def Name(cls):
-    return 'v8.browsing_%s' % cls.page_set.PLATFORM
+    return 'v8.browsing_%s' % cls.PLATFORM
 
   @classmethod
   def ValueCanBeAddedPredicate(cls, value, is_first_result):
     # TODO(crbug.com/610962): Remove this stopgap when the perf dashboard
     # is able to cope with the data load generated by TBMv2 metrics.
     if 'memory:chrome' in value.name:
       return ('renderer_processes' in value.name and
               not _IGNORED_MEMORY_STATS_RE.search(value.name))
     return (_V8_GC_HIGH_LEVEL_STATS_RE.search(value.name) and
             not _IGNORED_V8_STATS_RE.search(value.name))
 
   @classmethod
   def ShouldTearDownStateAfterEachStoryRun(cls):
     return True
 
 
 class V8DesktopBrowsingBenchmark(_V8BrowsingBenchmark):
-  page_set = page_sets.DesktopBrowsingSystemHealthStorySet
+  PLATFORM = 'desktop'
 
   @classmethod
   def ShouldDisable(cls, possible_browser):
     return possible_browser.platform.GetDeviceTypeName() != 'Desktop'
 
 
 class V8MobileBrowsingBenchmark(_V8BrowsingBenchmark):
-  page_set = page_sets.MobileBrowsingSystemHealthStorySet
+  PLATFORM = 'mobile'
 
   @classmethod
   def ShouldDisable(cls, possible_browser):
     return possible_browser.platform.GetDeviceTypeName() == 'Desktop'