Fix Chromium clang plugin warnings

webrtc/modules/audio_processing/aec/echo_cancellation.h

 /*
  *  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 47 matching lines @@
   AecLevel erle;
   AecLevel aNlp;
   float divergent_filter_fraction;
 } AecMetrics;
 
 struct AecCore;
 
 class ApmDataDumper;
 
 typedef struct Aec {
+  Aec();
+  ~Aec();
+
   std::unique_ptr<ApmDataDumper> data_dumper;
 
   int delayCtr;
   int sampFreq;
   int splitSampFreq;
   int scSampFreq;
   float sampFactor;  // scSampRate / sampFreq
   short skewMode;
   int bufSizeStart;
   int knownDelay;
@@ skipping 209 matching lines @@
 //  - handle                    : Pointer to the AEC instance.
 //
 // Return value:
 //  - AecCore pointer           : NULL for error.
 //
 struct AecCore* WebRtcAec_aec_core(void* handle);
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC_ECHO_CANCELLATION_H_