cc: Replace Region with SimpleEnclosedRegion for occlusion tracking

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': 1,
     'cc_unit_tests_source_files': [
       'animation/animation_unittest.cc',
       'animation/keyframed_animation_curve_unittest.cc',
       'animation/layer_animation_controller_unittest.cc',
       'animation/scroll_offset_animation_curve_unittest.cc',
       'animation/scrollbar_animation_controller_linear_fade_unittest.cc',
       'animation/scrollbar_animation_controller_thinning_unittest.cc',
       'animation/transform_operations_unittest.cc',
       'base/delayed_unique_notifier_unittest.cc',
       'base/float_quad_unittest.cc',
       'base/math_util_unittest.cc',
       'base/region_unittest.cc',
       'base/rolling_time_delta_history_unittest.cc',
       'base/scoped_ptr_vector_unittest.cc',
+      'base/simple_enclosed_region_unittest.cc',
       'base/tiling_data_unittest.cc',
       'base/unique_notifier_unittest.cc',
       'base/util_unittest.cc',
       'debug/micro_benchmark_controller_unittest.cc',
       'debug/rendering_stats_unittest.cc',
       'input/top_controls_manager_unittest.cc',
       'layers/content_layer_unittest.cc',
       'layers/contents_scaling_layer_unittest.cc',
       'layers/delegated_frame_provider_unittest.cc',
       'layers/delegated_frame_resource_collection_unittest.cc',
@@ skipping 383 matching lines @@
             'variables': {
               'test_suite_name': 'cc_perftests',
             },
             'includes': [ '../build/apk_test.gypi' ],
           },
         ],
       }
     ]
   ],
 }