Upgrade libsrtp to version 2.0 (second attempt)

BUILD.gn

 # Copyright (c) 2013 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.
 
 # This is the root build file for GN. GN will start processing by loading this
 # file, and recursively load all dependencies until all dependencies are either
 # resolved or known not to exist (which will cause the build to fail). So if
 # you add a new build file, there must be some path of dependencies from this
 # file to your new one or GN won't know about it.
 
@@ skipping 768 matching lines @@
       "//third_party/leveldatabase:leveldb_dbformat_test",
       "//third_party/leveldatabase:leveldb_env_test",
       "//third_party/leveldatabase:leveldb_filename_test",
       "//third_party/leveldatabase:leveldb_filter_block_test",
       "//third_party/leveldatabase:leveldb_log_test",
       "//third_party/leveldatabase:leveldb_skiplist_test",
       "//third_party/leveldatabase:leveldb_table_test",
       "//third_party/leveldatabase:leveldb_version_edit_test",
       "//third_party/leveldatabase:leveldb_write_batch_test",
       "//third_party/libjpeg_turbo:simd",
-      "//third_party/libsrtp:rdbx_driver",
-      "//third_party/libsrtp:replay_driver",
-      "//third_party/libsrtp:roc_driver",
-      "//third_party/libsrtp:rtpw",
-      "//third_party/libsrtp:srtp_driver",
-      "//third_party/libsrtp:srtp_test_aes_calc",
-      "//third_party/libsrtp:srtp_test_cipher_driver",
-      "//third_party/libsrtp:srtp_test_datatypes_driver",
-      "//third_party/libsrtp:srtp_test_env",
-      "//third_party/libsrtp:srtp_test_kernel_driver",
-      "//third_party/libsrtp:srtp_test_rand_gen",
-      "//third_party/libsrtp:srtp_test_sha1_driver",
-      "//third_party/libsrtp:srtp_test_stat_driver",
       "//third_party/opus:opus_compare",
       "//third_party/opus:opus_demo",
       "//third_party/opus:test_opus_api",
       "//third_party/opus:test_opus_decode",
       "//third_party/opus:test_opus_encode",
       "//third_party/opus:test_opus_padding",
       "//third_party/pdfium/third_party:fx_freetype",
       "//third_party/webrtc/system_wrappers:field_trial_default",
       "//third_party/webrtc/system_wrappers:metrics_default",
       "//ui/display/types",
@@ skipping 339 matching lines @@
       "//ui/display:display_unittests",
       "//ui/events:events_unittests",
       "//ui/gfx:gfx_unittests",
       "//ui/gl:gl_unittests",
       "//ui/keyboard:keyboard_unittests",
       "//ui/touch_selection:ui_touch_selection_unittests",
       "//url:url_unittests",
     ]
   }
 }