Fix a number of things in AudioEncoderDecoderIsac*

- Add max_bit_rate and max_payload_size_bytes to config structs.
- Fix support for 48 kHz sample rate.
- Fix iSAC-RED.
- Add method UpdateDecoderSampleRate().
- Update locking structure with a separate lock for local member
variables used by the encoder methods.

BUG=3926
COAUTHOR:kwiberg@webrtc.org

R=minyue@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/41659004

Cr-Commit-Position: refs/heads/master@{#8204}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8204 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/audio_coding/codecs/isac/main/interface/audio_encoder_isac.h

@@ -18,7 +18,7 @@ namespace webrtc {
 
 struct IsacFloat {
   typedef ISACStruct instance_type;
-  static const bool has_32kHz = true;
+  static const bool has_swb = true;
   static const bool has_redundant_encoder = false;
   static inline int16_t Control(instance_type* inst,
                                 int32_t rate,
@@ -102,6 +102,13 @@ struct IsacFloat {
     FATAL() << "Should never be called.";
     return -1;
   }
+  static inline int16_t SetMaxPayloadSize(instance_type* inst,
+                                          int16_t max_payload_size_bytes) {
+    return WebRtcIsac_SetMaxPayloadSize(inst, max_payload_size_bytes);
+  }
+  static inline int16_t SetMaxRate(instance_type* inst, int32_t max_bit_rate) {
+    return WebRtcIsac_SetMaxRate(inst, max_bit_rate);
+  }
 };
 
 typedef AudioEncoderDecoderIsacT<IsacFloat> AudioEncoderDecoderIsac;