Removed the dependency in GainControlImpl on the ProcessingComponent class

webrtc/modules/audio_processing/audio_processing_impl.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 180 matching lines @@
   void InitializeHighPassFilter()
       EXCLUSIVE_LOCKS_REQUIRED(crit_capture_);
   void InitializeNoiseSuppression()
       EXCLUSIVE_LOCKS_REQUIRED(crit_capture_);
   void InitializeLevelEstimator()
       EXCLUSIVE_LOCKS_REQUIRED(crit_capture_);
   void InitializeVoiceDetection()
       EXCLUSIVE_LOCKS_REQUIRED(crit_capture_);
   void InitializeEchoCanceller()
       EXCLUSIVE_LOCKS_REQUIRED(crit_render_, crit_capture_);
+  void InitializeGainController()
+      EXCLUSIVE_LOCKS_REQUIRED(crit_render_, crit_capture_);
   void InitializeEchoControlMobile()
       EXCLUSIVE_LOCKS_REQUIRED(crit_render_, crit_capture_);
   int InitializeLocked(const ProcessingConfig& config)
       EXCLUSIVE_LOCKS_REQUIRED(crit_render_, crit_capture_);
 
   // Capture-side exclusive methods possibly running APM in a multi-threaded
   // manner that are called with the render lock already acquired.
   int ProcessStreamLocked() EXCLUSIVE_LOCKS_REQUIRED(crit_capture_);
   bool output_copy_needed(bool is_data_processed) const
       EXCLUSIVE_LOCKS_REQUIRED(crit_capture_);
@@ skipping 131 matching lines @@
 
   struct ApmRenderState {
     std::unique_ptr<AudioConverter> render_converter;
     std::unique_ptr<AudioBuffer> render_audio;
   } render_ GUARDED_BY(crit_render_);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AUDIO_PROCESSING_IMPL_H_