Prefer device type instead of machine name for scale factor overrides.

content/test/gpu/gpu_tests/maps.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.
 
 """Runs a Google Maps pixel test.
 Performs several common navigation actions on the map (pan, zoom, rotate) then
 captures a screenshot and compares selected pixels against expected values"""
 
 import json
 import os
@@ skipping 36 matching lines @@
     # Even though the Maps test uses a fixed devicePixelRatio so that
     # it fetches all of the map tiles at the same resolution, on two
     # different devices with the same devicePixelRatio (a Retina
     # MacBook Pro and a Nexus 9), different scale factors of the final
     # screenshot are observed. Hack around this by specifying a scale
     # factor for these bots in the test expectations. This relies on
     # the test-machine-name argument being specified on the command
     # line.
     expected = self._ReadPixelExpectations(page)
     self._ValidateScreenshotSamples(
-        page.display_name, screenshot, expected, dpr)
+        tab, page.display_name, screenshot, expected, dpr)
 
   @staticmethod
   def SpinWaitOnRAF(tab, iterations, timeout=60):
     waitScript = r"""
       window.__spinWaitOnRAFDone = false;
       var iterationsLeft = %d;
 
       function spin() {
         iterationsLeft--;
         if (iterationsLeft == 0) {
@@ skipping 61 matching lines @@
 
   def CreateStorySet(self, options):
     story_set_path = os.path.join(
         path_util.GetChromiumSrcDir(), 'content', 'test', 'gpu', 'page_sets')
     ps = story_set_module.StorySet(
         archive_data_file='data/maps.json',
         base_dir=story_set_path,
         cloud_storage_bucket=story_module.PUBLIC_BUCKET)
     ps.AddStory(MapsPage(ps, ps.base_dir, self.GetExpectations()))
     return ps