Update audio code to use size_t more correctly, webrtc/common_audio/ portion.

webrtc/common_audio/sparse_fir_filter.cc

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/common_audio/sparse_fir_filter.h"
 
 #include "webrtc/base/checks.h"
 
 namespace webrtc {
 
 SparseFIRFilter::SparseFIRFilter(const float* nonzero_coeffs,
-                                 int num_nonzero_coeffs,
-                                 int sparsity,
-                                 int offset)
+                                 size_t num_nonzero_coeffs,
+                                 size_t sparsity,
+                                 size_t offset)
     : sparsity_(sparsity),
       offset_(offset),
       nonzero_coeffs_(nonzero_coeffs, nonzero_coeffs + num_nonzero_coeffs),
       state_(sparsity_ * (num_nonzero_coeffs - 1) + offset_, 0.f) {
-  CHECK_GE(num_nonzero_coeffs, 1);
-  CHECK_GE(sparsity, 1);
+  CHECK_GE(num_nonzero_coeffs, 1u);
+  CHECK_GE(sparsity, 1u);
 }
 
-void SparseFIRFilter::Filter(const float* in, int length, float* out) {
+void SparseFIRFilter::Filter(const float* in, size_t length, float* out) {
   // Convolves the input signal |in| with the filter kernel |nonzero_coeffs_|
   // taking into account the previous state.
-  for (int i = 0; i < length; ++i) {
+  for (size_t i = 0; i < length; ++i) {
     out[i] = 0.f;
     size_t j;
-    for (j = 0; i >= static_cast<int>(j) * sparsity_ + offset_ &&
+    for (j = 0; i >= j * sparsity_ + offset_ &&
                 j < nonzero_coeffs_.size(); ++j) {
       out[i] += in[i - j * sparsity_ - offset_] * nonzero_coeffs_[j];
     }
     for (; j < nonzero_coeffs_.size(); ++j) {
       out[i] += state_[i + (nonzero_coeffs_.size() - j - 1) * sparsity_] *
                 nonzero_coeffs_[j];
     }
   }
 
   // Update current state.
   if (state_.size() > 0u) {
-    if (length >= static_cast<int>(state_.size())) {
+    if (length >= state_.size()) {
       std::memcpy(&state_[0],
                   &in[length - state_.size()],
                   state_.size() * sizeof(*in));
     } else {
       std::memmove(&state_[0],
                    &state_[length],
                    (state_.size() - length) * sizeof(state_[0]));
       std::memcpy(&state_[state_.size() - length], in, length * sizeof(*in));
     }
   }
 }
 
 }  // namespace webrtc