Move WEBRTC_BUILD_LIBEVENT definition to base/BUILD.gn and base/base.gyp. This use all_dependent_co…

webrtc/build/common.gypi

 # Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 # This file contains common settings for building WebRTC components.
 
@@ skipping 326 matching lines @@
           }],
           ['clang==1', {
             'cflags': [
               '-Wimplicit-fallthrough',
               '-Wthread-safety',
               '-Winconsistent-missing-override',
             ],
           }],
         ],
       }],
-      ['enable_libevent==1', {
-        'defines': [
-          'WEBRTC_BUILD_LIBEVENT',
-        ],
-      }],
       ['target_arch=="arm64"', {
         'defines': [
           'WEBRTC_ARCH_ARM64',
           'WEBRTC_HAS_NEON',
         ],
       }],
       ['target_arch=="arm"', {
         'defines': [
           'WEBRTC_ARCH_ARM',
         ],
@@ skipping 223 matching lines @@
         }],
         ['OS=="freebsd"', {
           'defines': [
             'FREEBSD',
           ],
         }],
       ],
     },
   }, # target_defaults
 }