iSAC: Untangle some cyclic dependencies

webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.cc

Index: webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.cc
diff --git a/webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.cc b/webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.cc
index 54ec776672da81f2b3aba7cfde24fb03c153a8ae..e40a0e65989e820c05be06c23adbaa4f932c03f3 100644
--- a/webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.cc
+++ b/webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.cc
@@ -24,10 +24,10 @@
 #include "webrtc/modules/audio_coding/codecs/ilbc/audio_decoder_ilbc.h"
 #endif
 #ifdef WEBRTC_CODEC_ISACFX
-#include "webrtc/modules/audio_coding/codecs/isac/fix/include/audio_decoder_isacfix.h"
+#include "webrtc/modules/audio_coding/codecs/isac/fix/include/audio_decoder_isacfix.h"  // nogncheck

[kjellander_webrtc, 2017/01/26 15:22:00]

This is not possible to solve, or you're punting it to a future CL? If so, can
you add a reference to the bug here?

[kwiberg-webrtc, 2017/01/30 09:44:45]

This is how the gn docs recommend that you handle conditional #includes, since
gn doesn't actually understand the C preprocessor and always pretends that all
#include lines are in effect. So not possible to solve with current gn, and
"standard" enough that I'd argue a comment may not be needed. (Feel free to
disagree; I can add a comment if you still think one is called for.)

[kjellander_webrtc, 2017/01/30 10:45:34]

I hadn't seen it this before and I didn't know the check had that limitation.
Then this is of course fine. I wonder if we can document this somewhere
though... I'll make a comment in the GN check bug..

 #endif
 #ifdef WEBRTC_CODEC_ISAC
-#include "webrtc/modules/audio_coding/codecs/isac/main/include/audio_decoder_isac.h"
+#include "webrtc/modules/audio_coding/codecs/isac/main/include/audio_decoder_isac.h"  // nogncheck
 #endif
 #ifdef WEBRTC_CODEC_OPUS
 #include "webrtc/modules/audio_coding/codecs/opus/audio_decoder_opus.h"