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

webrtc/supplement.gypi

Index: webrtc/supplement.gypi
diff --git a/webrtc/supplement.gypi b/webrtc/supplement.gypi
index edccd4d81dbcc7aac9c19a87b94e03a0755fd1e6..20c1e666788058cb1052f86b10a35e0ebaddfa7b 100644
--- a/webrtc/supplement.gypi
+++ b/webrtc/supplement.gypi
@@ -14,6 +14,11 @@
     'mac_deployment_target%': '<(mac_deployment_target)',
     'use_sysroot%': '<(use_sysroot)',
     'build_with_chromium': 0,
+
+    # iLBC isn't included by default, but in standalone WebRTC we want it
+    # for testing.
+    'include_ilbc': 1,

[kjellander_webrtc, 2016/01/12 16:23:27]

ah, I missed this. Please make this (note the %):
'include_ilbc%': 1,

so it is possible to override it, even for the standalone build.
Please also test that it works to disable for the standalone build by:
webrtc/build/gyp_webrtc -Dinclude_iblc=0

Same for GN: please verify it's possible to turn it off with:
gn gen out/Default --args=rtc_include_ilbc=false

[kwiberg-webrtc, 2016/01/14 10:59:31]

This typo cost me at least half an hour. I couldn't figure out why setting the
variable had no effect... :-)
Patch set #3 should address all your concerns. Among other things, it no longer
modifies supplement.gypi at all.

+
     'conditions': [
       ['OS=="ios"', {
         # Default to using BoringSSL on iOS.