Adding build switch for Opus that supports 120ms ptime.

webrtc/modules/audio_coding/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.
 
 import("../../webrtc.gni")
 import("audio_coding.gni")
@@ skipping 854 matching lines @@
 }
 
 rtc_source_set("webrtc_opus_c") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
   sources = [
     "codecs/opus/opus_inst.h",
     "codecs/opus/opus_interface.c",
     "codecs/opus/opus_interface.h",
   ]
 
+  if (rtc_opus_support_120ms_ptime) {
+    defines += [ "WEBRTC_OPUS_SUPPORT_120MS_PTIME=1" ]
+  } else {
+    defines += [ "WEBRTC_OPUS_SUPPORT_120MS_PTIME=0" ]
+  }
+
   if (rtc_build_opus) {
     public_deps = [
       rtc_opus_dir,
     ]
   } else if (build_with_mozilla) {
     include_dirs = [ getenv("DIST") + "/include/opus" ]
   }
 
   deps = [
     "../..:webrtc_common",
@@ skipping 1220 matching lines @@
         ":neteq_unittest_proto",
       ]
     }
 
     if (!build_with_chromium && is_clang) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
   }
 }