Roll third_party/libsrtp to pick up arm64 GN build fix.

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 175 matching lines @@
   'src/third_party/ffmpeg':
    Var('chromium_git') + '/chromium/third_party/ffmpeg.git' + '@' + '58b10dfde70992faa033989ef9e3429c75e1175e',
 
   'src/third_party/libjingle/source/talk':
     Var('chromium_git') + '/external/webrtc/trunk/talk.git' + '@' + '8ede31b643e9f69dfd81fdf282cdf36f2ab56e62', # commit position 11108
 
   'src/third_party/usrsctp/usrsctplib':
     Var('chromium_git') + '/external/github.com/sctplab/usrsctp' + '@' + 'c60ec8b35c3fe6027d7a3faae89d1c8d7dd3ce98',
 
   'src/third_party/libsrtp':
-   Var('chromium_git') + '/chromium/deps/libsrtp.git' + '@' + '8a7662a400df7bdb0dc5cb7c0bf890dfa3481295', # from svn revision 295151
+   Var('chromium_git') + '/chromium/deps/libsrtp.git' + '@' + 'ebfcc9ac562411e12487036820fb1cbcd4bbe670', # from svn revision 295151
 
   'src/third_party/yasm/source/patched-yasm':
    Var('chromium_git') + '/chromium/deps/yasm/patched-yasm.git' + '@' + '4671120cd8558ce62ee8672ebf3eb6f5216f909b',
 
   'src/third_party/libjpeg_turbo':
    Var('chromium_git') + '/chromium/deps/libjpeg_turbo.git' + '@' + 'e4e75037f29745f1546b6ebf5cf532e841c04c2c',
 
   'src/third_party/flac':
    Var('chromium_git') + '/chromium/deps/flac.git' + '@' + '2c4b86af352b23498315c016dc207e3fb2733fc0',
 
@@ skipping 606 matching lines @@
         'src/tools',
     ],
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     'name': 'gyp',
     'pattern': '.',
     'action': ['python', 'src/build/gyp_chromium'],
   },
 ]