Hide ACMCodecDB::database_ behind accessors

webrtc/modules/audio_coding/main/acm2/audio_coding_module_impl.cc

 /*
  *  Copyright (c) 2012 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.
  */
 
@@ skipping 510 matching lines @@
   return 0;
 }
 
 // Get current receive frequency.
 int AudioCodingModuleImpl::ReceiveFrequency() const {
   WEBRTC_TRACE(webrtc::kTraceStream, webrtc::kTraceAudioCoding, id_,
                "ReceiveFrequency()");
 
   CriticalSectionScoped lock(acm_crit_sect_.get());
 
-  int codec_id = receiver_.last_audio_codec_id();
-
-  return codec_id < 0 ? receiver_.current_sample_rate_hz() :
-                        ACMCodecDB::database_[codec_id].plfreq;
+  auto codec_id = RentACodec::CodecIdFromIndex(receiver_.last_audio_codec_id());
+  return codec_id ? RentACodec::CodecInstById(*codec_id)->plfreq
+                  : receiver_.current_sample_rate_hz();
 }
 
 // Get current playout frequency.
 int AudioCodingModuleImpl::PlayoutFrequency() const {
   WEBRTC_TRACE(webrtc::kTraceStream, webrtc::kTraceAudioCoding, id_,
                "PlayoutFrequency()");
 
   CriticalSectionScoped lock(acm_crit_sect_.get());
 
   return receiver_.current_sample_rate_hz();
@@ skipping 237 matching lines @@
   return receiver_.LeastRequiredDelayMs();
 }
 
 void AudioCodingModuleImpl::GetDecodingCallStatistics(
       AudioDecodingCallStats* call_stats) const {
   receiver_.GetDecodingCallStatistics(call_stats);
 }
 
 }  // namespace acm2
 }  // namespace webrtc