Introduce CdmContext interface.

media/media.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,
     # Override to dynamically link the cras (ChromeOS audio) library.
     'use_cras%': 0,
     # Option e.g. for Linux distributions to link pulseaudio directly
@@ skipping 233 matching lines @@
         'base/bit_reader.h',
         'base/bit_reader_core.cc',
         'base/bit_reader_core.h',
         'base/bitstream_buffer.h',
         'base/buffering_state.h',
         'base/buffers.h',
         'base/byte_queue.cc',
         'base/byte_queue.h',
         'base/cdm_callback_promise.cc',
         'base/cdm_callback_promise.h',
+        'base/cdm_context.cc',
+        'base/cdm_context.h',
         'base/cdm_factory.cc',
         'base/cdm_factory.h',
         'base/cdm_promise.cc',
         'base/cdm_promise.h',
         'base/channel_mixer.cc',
         'base/channel_mixer.h',
         'base/channel_mixing_matrix.cc',
         'base/channel_mixing_matrix.h',
         'base/container_names.cc',
         'base/container_names.h',
@@ skipping 1715 matching lines @@
             '../build/isolate.gypi',
           ],
           'sources': [
             'media_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }