Only enable residual echo detector when needed in level controller perf tests.

webrtc/modules/audio_processing/level_controller/level_controller_complexity_unittest.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 187 matching lines @@
   SubmodulePerformanceTimer capture_timer;
   SubmodulePerformanceTimer total_timer;
 
   webrtc::Config config;
   AudioProcessing::Config apm_config;
   if (include_default_apm_processing) {
     config.Set<DelayAgnostic>(new DelayAgnostic(true));
     config.Set<ExtendedFilter>(new ExtendedFilter(true));
   }
   apm_config.level_controller.enabled = true;
+  apm_config.residual_echo_detector.enabled = include_default_apm_processing;
 
   std::unique_ptr<AudioProcessing> apm;
   apm.reset(AudioProcessing::Create(config));
   ASSERT_TRUE(apm.get());
   apm->ApplyConfig(apm_config);
 
   ASSERT_EQ(AudioProcessing::kNoError,
             apm->gain_control()->Enable(include_default_apm_processing));
   if (use_mobile_aec) {
     ASSERT_EQ(AudioProcessing::kNoError,
@@ skipping 128 matching lines @@
         RunTogetherWithApm("LevelControlAndDefaultMobileApm", 48000, 48000,
                            capture_input_sample_rate_hz,
                            capture_output_sample_rate_hz, num_channels, true,
                            true);
       }
     }
   }
 }
 
 }  // namespace webrtc