Fix Chromium clang plugin warnings

webrtc/modules/audio_processing/level_controller/signal_classifier.cc

 /*
  *  Copyright (c) 2016 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 75 matching lines @@
     return SignalClassifier::SignalType::kStationary;
   } else if (num_highly_nonstationary_bands > 15) {
     return SignalClassifier::SignalType::kHighlyNonStationary;
   } else {
     return SignalClassifier::SignalType::kNonStationary;
   }
 }
 
 }  // namespace
 
+SignalClassifier::FrameExtender::FrameExtender(size_t frame_size,
+                                               size_t extended_frame_size)
+    : x_old_(extended_frame_size - frame_size, 0.f) {}
+
+SignalClassifier::FrameExtender::~FrameExtender() = default;
+
 void SignalClassifier::FrameExtender::ExtendFrame(
     rtc::ArrayView<const float> x,
     rtc::ArrayView<float> x_extended) {
   RTC_DCHECK_EQ(x_old_.size() + x.size(), x_extended.size());
   std::copy(x_old_.data(), x_old_.data() + x_old_.size(), x_extended.data());
   std::copy(x.data(), x.data() + x.size(), x_extended.data() + x_old_.size());
   std::copy(x_extended.data() + x_extended.size() - x_old_.size(),
             x_extended.data() + x_extended.size(), x_old_.data());
 }
 
@@ skipping 51 matching lines @@
     last_signal_type_ = *signal_type;
     consistent_classification_counter_ = 3;
   }
 
   if (consistent_classification_counter_ > 0) {
     *signal_type = SignalClassifier::SignalType::kNonStationary;
   }
 }
 
 }  // namespace webrtc