Pass accurate contentsScale to LayerImpl.

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_tests_source_files': [
       'hash_pair_unittest.cc',
       'active_animation_unittest.cc',
+      'contents_scaling_layer_unittest.cc',
       'damage_tracker_unittest.cc',
       'delay_based_time_source_unittest.cc',
       'draw_quad_unittest.cc',
       'delegated_renderer_layer_impl_unittest.cc',
       'frame_rate_controller_unittest.cc',
       'heads_up_display_unittest.cc',
       'keyframed_animation_curve_unittest.cc',
       'layer_animation_controller_unittest.cc',
       'layer_impl_unittest.cc',
       'layer_iterator_unittest.cc',
@@ skipping 134 matching lines @@
           'variables': {
             'test_suite_name': 'cc_unittests',
             'input_shlib_path': '<(SHARED_LIB_DIR)/<(SHARED_LIB_PREFIX)cc_unittests<(SHARED_LIB_SUFFIX)',
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],
 }