Disable some tests on Nexus 5X reference again

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 os
 import shlex
 
 from core import path_util
 from core import perf_benchmark
 from page_sets import google_pages
 
@@ skipping 12 matching lines @@
 
 @benchmark.Disabled('win')        # crbug.com/416502
 class V8Top25(perf_benchmark.PerfBenchmark):
   """Measures V8 GC metrics on the while scrolling down the top 25 web pages.
 
   http://www.chromium.org/developers/design-documents/rendering-benchmarks"""
   test = v8_gc_times.V8GCTimes
   page_set = page_sets.V8Top25SmoothPageSet
 
   @classmethod
+  def ShouldDisable(cls, possible_browser):  # http://crbug.com/597656
+    return (possible_browser.browser_type == 'reference' and
+            possible_browser.platform.GetDeviceTypeName() == 'Nexus 5X')
+
+  @classmethod
   def Name(cls):
     return 'v8.top_25_smooth'
 
 
 @benchmark.Enabled('android')
 class V8KeyMobileSites(perf_benchmark.PerfBenchmark):
   """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
@@ skipping 182 matching lines @@
   def Name(cls):
     return 'v8.google'
 
   @classmethod
   def ShouldDisable(cls, possible_browser):
     return cls.IsSvelte(possible_browser) # http://crbug.com/596556
 
   @classmethod
   def ShouldTearDownStateAfterEachStoryRun(cls):
     return True