Update includes for webrtc/{base => rtc_base} rename (1/3)

webrtc/modules/audio_mixer/sine_wave_generator.cc

 /*
  *  Copyright (c) 2017 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/modules/audio_mixer/sine_wave_generator.h"
 
 #include <math.h>
 
-#include "webrtc/base/safe_conversions.h"
+#include "webrtc/rtc_base/safe_conversions.h"
 
 namespace webrtc {
 
 namespace {
 constexpr float kPi = 3.14159265f;
 }  // namespace
 
 void SineWaveGenerator::GenerateNextFrame(AudioFrame* frame) {
   RTC_DCHECK(frame);
   int16_t* frame_data = frame->mutable_data();
   for (size_t i = 0; i < frame->samples_per_channel_; ++i) {
     for (size_t ch = 0; ch < frame->num_channels_; ++ch) {
       frame_data[frame->num_channels_ * i + ch] =
           rtc::saturated_cast<int16_t>(amplitude_ * sinf(phase_));
     }
     phase_ += wave_frequency_hz_ * 2 * kPi / frame->sample_rate_hz_;
   }
 }
 }  // namespace webrtc