Add a gyp/gn variable for whether to use iLBC or not

webrtc/modules/audio_coding/neteq/neteq.gypi

Index: webrtc/modules/audio_coding/neteq/neteq.gypi
diff --git a/webrtc/modules/audio_coding/neteq/neteq.gypi b/webrtc/modules/audio_coding/neteq/neteq.gypi
index e424ab5bf96cdb8c34d99fbb325a9071fdf90895..50b8425c87e0684a077cb1bdf52245405f4a5991 100644
--- a/webrtc/modules/audio_coding/neteq/neteq.gypi
+++ b/webrtc/modules/audio_coding/neteq/neteq.gypi
@@ -15,6 +15,10 @@
     ],
     'neteq_defines': [],
     'conditions': [
+      ['include_ilbc==1', {
+        'codecs': ['ilbc',],
+        'neteq_defines': ['WEBRTC_CODEC_ILBC',],
+      }],
       ['include_opus==1', {
         'codecs': ['webrtc_opus',],
         'neteq_defines': ['WEBRTC_CODEC_OPUS',],
@@ -32,10 +36,6 @@
         'codecs': ['g722',],
         'neteq_defines': ['WEBRTC_CODEC_G722',],
       }],
-      ['build_with_mozilla==0 and build_with_chromium==0', {
-        'codecs': ['ilbc',],
-        'neteq_defines': ['WEBRTC_CODEC_ILBC',],
-      }],
     ],
     'neteq_dependencies': [
       '<@(codecs)',