Remove use_openssl from webrtc

webrtc/supplement.gypi

 {
   'variables': {
     'variables': {
       'webrtc_root%': '<(DEPTH)/webrtc',
       # Override the defaults in Chromium's build/common.gypi.
       # Needed for ARC and libc++.
       'mac_sdk_min%': '10.11',
       'mac_deployment_target%': '10.7',
     },
     'webrtc_root%': '<(webrtc_root)',
     'mac_deployment_target%': '<(mac_deployment_target)',
     'use_sysroot%': '<(use_sysroot)',
     'build_with_chromium': 0,
     'conditions': [
       ['OS=="ios"', {
-        # Default to using BoringSSL on iOS.
-        'use_openssl%': 1,
-
         # Set target_subarch for if not already set. This is needed because the
         # Chromium iOS toolchain relies on target_subarch being set.
         'conditions': [
           ['target_arch=="arm" or target_arch=="ia32"', {
             'target_subarch%': 'arm32',
           }],
           ['target_arch=="arm64" or target_arch=="x64"', {
             'target_subarch%': 'arm64',
           }],
         ],
@@ skipping 20 matching lines @@
             ],
             'sources': [
               '<(webrtc_root)/build/sanitizers/tsan_suppressions_webrtc.cc',
             ],
           }],
         ],
       }],
     ],
   },
 }