Revert "Disabled v8.detached_context_age_in_gc benchmark due to crash"

tools/perf/benchmarks/v8.py

 # Copyright 2014 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 page_sets
 from measurements import v8_detached_context_age_in_gc
 from measurements import v8_gc_times
 from telemetry import benchmark
 
 
@@ skipping 26 matching lines @@
   """Measures V8 GC metrics on the while scrolling down key mobile sites.
 
   http://www.chromium.org/developers/design-documents/rendering-benchmarks"""
   test = v8_gc_times.V8GCTimes
   page_set = page_sets.KeyMobileSitesSmoothPageSet
 
   @classmethod
   def Name(cls):
     return 'v8.key_mobile_sites_smooth'
 
-@benchmark.Disabled  # http://crbug.com/469146
 class V8DetachedContextAgeInGC(benchmark.Benchmark):
   """Measures the number of GCs needed to collect a detached context.
 
   http://www.chromium.org/developers/design-documents/rendering-benchmarks"""
   test = v8_detached_context_age_in_gc.V8DetachedContextAgeInGC
   page_set = page_sets.PageReloadCasesPageSet
 
   @classmethod
   def Name(cls):
     return 'v8.detached_context_age_in_gc'