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

webrtc/modules/audio_coding/neteq/background_noise.cc

Index: webrtc/modules/audio_coding/neteq/background_noise.cc
diff --git a/webrtc/modules/audio_coding/neteq/background_noise.cc b/webrtc/modules/audio_coding/neteq/background_noise.cc
index a59f444c503f098d545465d25f0a55c7a8d105a9..d3df26902cdc2e34159ef4a92b780867eb10e749 100644
--- a/webrtc/modules/audio_coding/neteq/background_noise.cc
+++ b/webrtc/modules/audio_coding/neteq/background_noise.cc
@@ -21,6 +21,9 @@
 
 namespace webrtc {
 
+// static
+const size_t BackgroundNoise::kMaxLpcOrder;
+
 BackgroundNoise::BackgroundNoise(size_t num_channels)
     : num_channels_(num_channels),
       channel_parameters_(new ChannelParameters[num_channels_]),
@@ -150,7 +153,7 @@ const int16_t* BackgroundNoise::FilterState(size_t channel) const {
 void BackgroundNoise::SetFilterState(size_t channel, const int16_t* input,
                                      size_t length) {
   assert(channel < num_channels_);
-  length = std::min(length, static_cast<size_t>(kMaxLpcOrder));
+  length = std::min(length, kMaxLpcOrder);
   memcpy(channel_parameters_[channel].filter_state, input,
          length * sizeof(int16_t));
 }
@@ -165,7 +168,7 @@ int16_t BackgroundNoise::ScaleShift(size_t channel) const {
 }
 
 int32_t BackgroundNoise::CalculateAutoCorrelation(
-    const int16_t* signal, int length, int32_t* auto_correlation) const {
+    const int16_t* signal, size_t length, int32_t* auto_correlation) const {
   int16_t signal_max = WebRtcSpl_MaxAbsValueW16(signal, length);
   int correlation_scale = kLogVecLen -
       WebRtcSpl_NormW32(signal_max * signal_max);
@@ -247,7 +250,7 @@ void BackgroundNoise::SaveParameters(size_t channel,
   residual_energy = residual_energy << norm_shift;
 
   // Calculate scale and shift factor.
-  parameters.scale = WebRtcSpl_SqrtFloor(residual_energy);
+  parameters.scale = static_cast<int16_t>(WebRtcSpl_SqrtFloor(residual_energy));
   // Add 13 to the |scale_shift_|, since the random numbers table is in
   // Q13.
   // TODO(hlundin): Move the "13" to where the |scale_shift_| is used?