Remove Opus from DEPS and import a local copy

DEPS

 # This file is used to manage the dependencies of the Chromium src repo. It is
 # used by gclient to determine what version of each dependency to check out, and
 # where.
 #
 # For more information, please refer to the official documentation:
 #   https://sites.google.com/a/chromium.org/dev/developers/how-tos/get-the-code
 #
 # When adding a new dependency, please update the top-level .gitignore file
 # to list the dependency's destination directory.
 #
@@ skipping 222 matching lines @@
 
   'src/third_party/libphonenumber/dist':
     Var('chromium_git') + '/external/libphonenumber.git' + '@' + 'a4da30df63a097d67e3c429ead6790ad91d36cf4',
 
   'src/third_party/webpagereplay':
    Var('chromium_git') + '/external/github.com/chromium/web-page-replay.git' + '@' + '3cd3a3f6f06a1b87b14b9162c7eb16d23d141241',
 
   'src/third_party/pywebsocket/src':
     Var('chromium_git') + '/external/github.com/google/pywebsocket.git' + '@' + '2d7b73c3acbd0f41dcab487ae5c97c6feae06ce2',
 
-  'src/third_party/opus/src':
-   Var('chromium_git') + '/chromium/deps/opus.git' + '@' + 'aa32042a50f2cbe0ff9d339948cb4712f5cc3d6e',
-
   'src/media/cdm/api':
    Var('chromium_git') + '/chromium/cdm.git' + '@' + '245af7782c9f54d776722a2c7b53372ee040e5fc',
 
   'src/third_party/mesa/src':
    Var('chromium_git') + '/chromium/deps/mesa.git' + '@' + 'ef811c6bd4de74e13e7035ca882cc77f85793fef',
 
   'src/third_party/ced/src':
     Var('chromium_git') + '/external/github.com/google/compact_enc_det.git' + '@' + '9012c0ab648025dd0f8df14294bf5d6d73793ac9',
 
   'src/third_party/cld_2/src':
@@ skipping 714 matching lines @@
     'name': 'doclava',
     'pattern': '.',
     'action': ['python',
                'src/build/android/download_doclava.py',
     ],
   },
 ]
 
 # ANGLE manages DEPS that it also owns the build files for, such as dEQP.
 recursedeps = [("src/third_party/angle", "DEPS.chromium")]