Update Maps pixel test.

content/test/gpu/gpu_tests/cloud_storage_test_base.py

Index: content/test/gpu/gpu_tests/cloud_storage_test_base.py
diff --git a/content/test/gpu/gpu_tests/cloud_storage_test_base.py b/content/test/gpu/gpu_tests/cloud_storage_test_base.py
index d218d3ff9512b8edc615503ac6dc78ea23d400f2..fee9ba2b5f3cfebfffdf641e35251be6009e3d28 100644
--- a/content/test/gpu/gpu_tests/cloud_storage_test_base.py
+++ b/content/test/gpu/gpu_tests/cloud_storage_test_base.py
@@ -5,6 +5,7 @@
 """Base classes for a test and validator which upload results
 (reference images, error images) to cloud storage."""
 
+import logging
 import os
 import re
 import tempfile
@@ -23,8 +24,25 @@ default_generated_data_dir = os.path.join(test_data_dir, 'generated')
 
 error_image_cloud_storage_bucket = 'chromium-browser-gpu-tests'
 
-def _CompareScreenshotSamples(screenshot, expectations, device_pixel_ratio):
+def _CompareScreenshotSamples(screenshot, expectations, device_pixel_ratio,
+                              test_machine_name):
+  # First scan through the expectations and see if there are any scale
+  # factor overrides that would preempt the device pixel ratio. This
+  # is mainly a workaround for complex tests like the Maps test.
+  if test_machine_name:
+    for expectation in expectations:
+      if "scale_factor_overrides" in expectation:
+        for override in expectation["scale_factor_overrides"]:
+          if override["machine_name"] in test_machine_name:
+            logging.warning('Overriding device_pixel_ratio ' +
+                            str(device_pixel_ratio) + ' with scale factor ' +
+                            str(override["scale_factor"]))
+            device_pixel_ratio = override["scale_factor"]
+            break
+        break
   for expectation in expectations:
+    if "scale_factor_overrides" in expectation:
+      continue
     location = expectation["location"]
     size = expectation["size"]
     x0 = int(location[0] * device_pixel_ratio)
@@ -48,6 +66,7 @@ def _CompareScreenshotSamples(screenshot, expectations, device_pixel_ratio):
             expectation["color"][2])
         if not actual_color.IsEqual(expected_color, expectation["tolerance"]):
           raise page_test.Failure('Expected pixel at ' + str(location) +
+              ' (actual pixel (' + str(x) + ', ' + str(y) + ')) ' +
               ' to be ' +
               str(expectation["color"]) + " but got [" +
               str(actual_color.r) + ", " +
@@ -219,7 +238,8 @@ class ValidatorBase(gpu_test_base.ValidatorBase):
        a Failure and dumps the screenshot locally or cloud storage depending on
        what machine the test is being run."""
     try:
-      _CompareScreenshotSamples(screenshot, expectations, device_pixel_ratio)
+      _CompareScreenshotSamples(screenshot, expectations, device_pixel_ratio,
+                                self.options.test_machine_name)
     except page_test.Failure:
       image_name = self._UrlToImageName(url)
       if self.options.test_machine_name: