cc: Made image comparison for pixel tests error tolerant.

cc/cc_tests.gyp

 # Copyright (c) 2012 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.
 
 {
   'variables': {
     'chromium_code': 0,
     'cc_unit_tests_source_files': [
       'animation/animation_unittest.cc',
       'layers/content_layer_unittest.cc',
@@ skipping 238 matching lines @@
       # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
       'msvs_disabled_warnings': [ 4267, ],
     },
     {
       'target_name': 'cc_test_utils',
       'type': 'static_library',
       'include_dirs': [
         '..'
       ],
       'sources': [
+        'test/pixel_comparator.cc',
+        'test/pixel_comparator.h',
         'test/pixel_test_utils.cc',
         'test/pixel_test_utils.h',
       ],
       'dependencies': [
         '../skia/skia.gyp:skia',
         '../ui/ui.gyp:ui',  # for png_codec
       ],
     },
   ],
   'conditions': [
@@ skipping 22 matching lines @@
           'variables': {
             'test_suite_name': 'cc_perftests',
             'input_shlib_path': '<(SHARED_LIB_DIR)/<(SHARED_LIB_PREFIX)cc_perftests<(SHARED_LIB_SUFFIX)',
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }]
   ],
 }