Fix compilation issue detected by internal tool.

webrtc/modules/audio_processing/aec3/subtractor.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.
  */
 
@@ skipping 29 matching lines @@
 std::vector<size_t> Subtractor::NumBlocksInRenderSums() const {
   if (kMainFilterSizePartitions != kShadowFilterSizePartitions) {
     return {kMainFilterSizePartitions, kShadowFilterSizePartitions};
   } else {
     return {kMainFilterSizePartitions};
   }
 }
 
 Subtractor::Subtractor(ApmDataDumper* data_dumper,
                        Aec3Optimization optimization)
-    : data_dumper_(data_dumper),
+    : fft_(),
+      data_dumper_(data_dumper),
       optimization_(optimization),
       main_filter_(kMainFilterSizePartitions, true, optimization, data_dumper_),
       shadow_filter_(kShadowFilterSizePartitions,
                      false,
                      optimization,
                      data_dumper_) {
   RTC_DCHECK(data_dumper_);
 }
 
 Subtractor::~Subtractor() {}
@@ skipping 47 matching lines @@
                     shadow_filter_.SizePartitions(), saturation, &G);
   shadow_filter_.Adapt(X_buffer, G);
   data_dumper_->DumpRaw("aec3_subtractor_G_shadow", G.re);
   data_dumper_->DumpRaw("aec3_subtractor_G_shadow", G.im);
 
   main_filter_.DumpFilter("aec3_subtractor_H_main");
   shadow_filter_.DumpFilter("aec3_subtractor_H_shadow");
 }
 
 }  // namespace webrtc