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

webrtc/BUILD.gn

 # Copyright (c) 2014 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.
 
 # TODO(kjellander): Rebase this to webrtc/build/common.gypi changes after r6330.
 
@@ skipping 157 matching lines @@
 
     if (is_clang) {
       cflags += [
         "-Wimplicit-fallthrough",
         "-Wthread-safety",
         "-Winconsistent-missing-override",
       ]
     }
   }
 
-  if (rtc_enable_libevent) {
-    defines += [ "WEBRTC_BUILD_LIBEVENT" ]
-  }
-
   if (current_cpu == "arm64") {
     defines += [ "WEBRTC_ARCH_ARM64" ]
     defines += [ "WEBRTC_HAS_NEON" ]
   }
 
   if (current_cpu == "arm") {
     defines += [ "WEBRTC_ARCH_ARM" ]
     if (arm_version >= 7) {
       defines += [ "WEBRTC_ARCH_ARM_V7" ]
       if (arm_use_neon) {
@@ skipping 466 matching lines @@
     if (is_ios || (is_mac && target_cpu != "x86")) {
       defines = [ "CARBON_DEPRECATED=YES" ]
     }
     if (is_clang) {
       # Suppress warnings from the Chromium Clang plugin.
       # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
       configs -= [ "//build/config/clang:find_bad_constructs" ]
     }
   }
 }