iSAC: Make separate AudioEncoder and AudioDecoder objects

webrtc/modules/audio_coding/codecs/isac/isac.gypi

Index: webrtc/modules/audio_coding/codecs/isac/isac.gypi
diff --git a/webrtc/modules/audio_coding/codecs/isac/isac.gypi b/webrtc/modules/audio_coding/codecs/isac/isac.gypi
index 50cc867b2343685003ea439797967ca3a974eb28..8ecc2dc414fa91487286fbd2e03127ebd2fd268b 100644
--- a/webrtc/modules/audio_coding/codecs/isac/isac.gypi
+++ b/webrtc/modules/audio_coding/codecs/isac/isac.gypi
@@ -15,6 +15,7 @@
         '<(webrtc_root)/common_audio/common_audio.gyp:common_audio',
         'audio_decoder_interface',
         'audio_encoder_interface',
+        'isac_common',
       ],
       'include_dirs': [
         'main/interface',
@@ -27,8 +28,6 @@
         ],
       },
       'sources': [
-        'audio_encoder_isac_t.h',
-        'audio_encoder_isac_t_impl.h',
         'main/interface/audio_encoder_isac.h',
         'main/interface/isac.h',
         'main/source/arith_routines.c',