Update a ton of audio code to use size_t more correctly and in general reduce

webrtc/modules/audio_processing/agc/mock_agc.h

Index: webrtc/modules/audio_processing/agc/mock_agc.h
diff --git a/webrtc/modules/audio_processing/agc/mock_agc.h b/webrtc/modules/audio_processing/agc/mock_agc.h
index 1c36a055ecac6588fdef34dd718d5849254c5982..13dbd2edd53a727b50c8c6259ff164cee3f71398 100644
--- a/webrtc/modules/audio_processing/agc/mock_agc.h
+++ b/webrtc/modules/audio_processing/agc/mock_agc.h
@@ -20,8 +20,8 @@ namespace webrtc {
 
 class MockAgc : public Agc {
  public:
-  MOCK_METHOD2(AnalyzePreproc, float(const int16_t* audio, int length));
-  MOCK_METHOD3(Process, int(const int16_t* audio, int length,
+  MOCK_METHOD2(AnalyzePreproc, float(const int16_t* audio, size_t length));
+  MOCK_METHOD3(Process, int(const int16_t* audio, size_t length,
                             int sample_rate_hz));
   MOCK_METHOD1(GetRmsErrorDb, bool(int* error));
   MOCK_METHOD0(Reset, void());