Disable v8.google on Nexus 5/7.

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 re
 
 from core import path_util
 from core import perf_benchmark
 from page_sets import google_pages
 
@@ skipping 280 matching lines @@
         cloud_storage_bucket=story.PARTNER_BUCKET)
     story_set.AddStory(google_pages.AdwordCampaignDesktopPage(story_set))
     return story_set
 
   @classmethod
   def Name(cls):
     return 'v8.google'
 
   @classmethod
   def ShouldDisable(cls, possible_browser):
-    return cls.IsSvelte(possible_browser) # http://crbug.com/596556
+    if cls.IsSvelte(possible_browser): # http://crbug.com/596556
+      return True
+    # http://crbug.com/623576
+    if (possible_browser.platform.GetDeviceTypeName() == 'Nexus 5' or
+        possible_browser.platform.GetDeviceTypeName() == 'Nexus 7'):
+      return True
+    return False
 
   @classmethod
   def ShouldTearDownStateAfterEachStoryRun(cls):
     return True