Revert of [tools/perf] Disable page_cycler_v2.typical_25 benchmark

tools/perf/benchmarks/page_cycler_v2.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.
 
 """The page cycler v2.
 
 For details, see design doc:
 https://docs.google.com/document/d/1EZQX-x3eEphXupiX-Hq7T4Afju5_sIdxPWYetj7ynd0
 """
 
 from core import perf_benchmark
 import page_sets
 
-from telemetry import benchmark
 from telemetry.page import cache_temperature
 from telemetry.timeline import tracing_category_filter
 from telemetry.web_perf import timeline_based_measurement
 
-
 class _PageCyclerV2(perf_benchmark.PerfBenchmark):
   def CreateTimelineBasedMeasurementOptions(self):
     cat_filter = tracing_category_filter.TracingCategoryFilter(
         filter_string='*,blink.console,navigation,blink.user_timing,loading')
 
     tbm_options = timeline_based_measurement.Options(
         overhead_level=cat_filter)
     tbm_options.SetTimelineBasedMetric('firstPaintMetric')
     return tbm_options
 
-
-@benchmark.Disabled('all')  # crbug.com/615178
 class PageCyclerV2Typical25(_PageCyclerV2):
   """Page load time benchmark for a 25 typical web pages.
 
   Designed to represent typical, not highly optimized or highly popular web
   sites. Runs against pages recorded in June, 2014.
   """
   options = {'pageset_repeat': 3}
 
   @classmethod
   def Name(cls):
     return 'page_cycler_v2.typical_25'
 
   def CreateStorySet(self, options):
     return page_sets.Typical25PageSet(run_no_page_interactions=True,
         cache_temperatures=[
           cache_temperature.PCV1_COLD, cache_temperature.PCV1_WARM])