Disable failing blink_perf.shadow_dom on N5X

tools/perf/benchmarks/blink_perf.py

 # Copyright 2013 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
 
 from core import path_util
 from core import perf_benchmark
 
 from telemetry import benchmark
@@ skipping 275 matching lines @@
 class BlinkPerfSVG(_BlinkPerfBenchmark):
   tag = 'svg'
   subdir = 'SVG'
 
 
 @benchmark.Owner(emails=['hayato@chromium.org'])
 class BlinkPerfShadowDOM(_BlinkPerfBenchmark):
   tag = 'shadow_dom'
   subdir = 'ShadowDOM'
 
+  @classmethod
+  def ShouldDisable(cls, possible_browser):  # http://crbug.com/702319
+    return possible_browser.platform.GetDeviceTypeName() == 'Nexus 5X'
+
 
 # This benchmark is for local testing, doesn't need to run on bots.
 @benchmark.Disabled('all')
 @benchmark.Owner(emails=['tyoshino@chromium.org', 'hiroshige@chromium.org'])
 class BlinkPerfXMLHttpRequest(_BlinkPerfBenchmark):
   tag = 'xml_http_request'
   subdir = 'XMLHttpRequest'
 
 
 # Disabled on Windows and ChromeOS due to https://crbug.com/521887
@@ skipping 12 matching lines @@
 
   def CreateStorySet(self, options):
     path = os.path.join(BLINK_PERF_BASE_DIR, self.subdir)
     return CreateStorySetFromPath(
         path, SKIPPED_FILE,
         shared_page_state_class=_SharedPywebsocketPageState)
 
   @classmethod
   def ShouldDisable(cls, possible_browser):
     return cls.IsSvelte(possible_browser)  # http://crbug.com/551950