Pass ownership of external encoders to the ACM

webrtc/modules/audio_coding/acm2/codec_manager.h

 /*
  *  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.
  */
 
@@ skipping 23 matching lines @@
 
   // Parses the given specification. On success, returns true and updates the
   // stored CodecInst and stack parameters; on error, returns false.
   bool RegisterEncoder(const CodecInst& send_codec);
 
   static CodecInst ForgeCodecInst(const AudioEncoder* external_speech_encoder);
 
   const CodecInst* GetCodecInst() const {
     return send_codec_inst_ ? &*send_codec_inst_ : nullptr;
   }
+
+  void UnsetCodecInst() { send_codec_inst_ = rtc::Optional<CodecInst>(); }
+
   const RentACodec::StackParameters* GetStackParams() const {
     return &codec_stack_params_;
   }
   RentACodec::StackParameters* GetStackParams() { return &codec_stack_params_; }
 
   bool SetCopyRed(bool enable);
 
   bool SetVAD(bool enable, ACMVADMode mode);
 
   bool SetCodecFEC(bool enable_codec_fec);
 
  private:
   rtc::ThreadChecker thread_checker_;
   rtc::Optional<CodecInst> send_codec_inst_;
   RentACodec::StackParameters codec_stack_params_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(CodecManager);
 };
 
 }  // namespace acm2
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_AUDIO_CODING_ACM2_CODEC_MANAGER_H_