aura: Remove CreateOffscreenContext from ui::ContextFactory.

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',
@@ skipping 81 matching lines @@
     ],
     'cc_tests_support_files': [
       'test/animation_test_common.cc',
       'test/animation_test_common.h',
       'test/fake_content_layer.cc',
       'test/fake_content_layer.h',
       'test/fake_content_layer_client.cc',
       'test/fake_content_layer_client.h',
       'test/fake_content_layer_impl.cc',
       'test/fake_content_layer_impl.h',
-      'test/fake_context_provider.cc',
-      'test/fake_context_provider.h',
       'test/fake_delegated_renderer_layer.cc',
       'test/fake_delegated_renderer_layer.h',
       'test/fake_delegated_renderer_layer_impl.cc',
       'test/fake_delegated_renderer_layer_impl.h',
       'test/fake_impl_proxy.h',
       'test/fake_layer_tree_host_client.cc',
       'test/fake_layer_tree_host_client.h',
       'test/fake_layer_tree_host_impl.cc',
       'test/fake_layer_tree_host_impl_client.cc',
       'test/fake_layer_tree_host_impl_client.h',
@@ skipping 225 matching lines @@
               'test_suite_name': 'cc_perftests',
               'input_shlib_path': '<(SHARED_LIB_DIR)/<(SHARED_LIB_PREFIX)cc_perftests<(SHARED_LIB_SUFFIX)',
             },
             'includes': [ '../build/apk_test.gypi' ],
           },
         ],
       }
     ]
   ],
 }