Update audio code to use size_t more correctly,

webrtc/modules/audio_coding/codecs/isac/fix/interface/audio_encoder_isacfix.h

Index: webrtc/modules/audio_coding/codecs/isac/fix/interface/audio_encoder_isacfix.h
diff --git a/webrtc/modules/audio_coding/codecs/isac/fix/interface/audio_encoder_isacfix.h b/webrtc/modules/audio_coding/codecs/isac/fix/interface/audio_encoder_isacfix.h
index 02b5d3cab881828884575d1c3e121aef102d3d26..e6db42945e850497e902bbef2abde989ae016c13 100644
--- a/webrtc/modules/audio_coding/codecs/isac/fix/interface/audio_encoder_isacfix.h
+++ b/webrtc/modules/audio_coding/codecs/isac/fix/interface/audio_encoder_isacfix.h
@@ -40,14 +40,14 @@ struct IsacFix {
   }
   static inline int DecodeInternal(instance_type* inst,
                                    const uint8_t* encoded,
-                                   int16_t len,
+                                   size_t len,
                                    int16_t* decoded,
                                    int16_t* speech_type) {
     return WebRtcIsacfix_Decode(inst, encoded, len, decoded, speech_type);
   }
-  static inline int16_t DecodePlc(instance_type* inst,
-                                  int16_t* decoded,
-                                  int16_t num_lost_frames) {
+  static inline size_t DecodePlc(instance_type* inst,
+                                 int16_t* decoded,
+                                 size_t num_lost_frames) {
     return WebRtcIsacfix_DecodePlc(inst, decoded, num_lost_frames);
   }
   static inline int16_t DecoderInit(instance_type* inst) {
@@ -104,7 +104,7 @@ struct IsacFix {
   }
   static inline int16_t UpdateBwEstimate(instance_type* inst,
                                          const uint8_t* encoded,
-                                         int32_t packet_size,
+                                         size_t packet_size,
                                          uint16_t rtp_seq_number,
                                          uint32_t send_ts,
                                          uint32_t arr_ts) {
@@ -147,7 +147,7 @@ class AudioEncoderDecoderMutableIsacFix
                       int16_t* decoded,
                       SpeechType* speech_type) override;
   bool HasDecodePlc() const override;
-  int DecodePlc(int num_frames, int16_t* decoded) override;
+  size_t DecodePlc(size_t num_frames, int16_t* decoded) override;
   int Init() override;
   int IncomingPacket(const uint8_t* payload,
                      size_t payload_len,