Removed the inheritance from ProcessingComponent for EchoCancellerImpl.

BUG=webrtc:5352

Committed: https://crrev.com/3af0a009f8a7f2dfb630a4f4730044cbbd95bee8
Cr-Commit-Position: refs/heads/master@{#11876}

Review URL: https://codereview.webrtc.org/1761813002

Cr-Commit-Position: refs/heads/master@{#11881}
diff --git a/webrtc/modules/audio_processing/audio_processing_impl.h b/webrtc/modules/audio_processing/audio_processing_impl.h
index 4a28761..560920b 100644
--- a/webrtc/modules/audio_processing/audio_processing_impl.h
+++ b/webrtc/modules/audio_processing/audio_processing_impl.h
@@ -196,6 +196,8 @@
       EXCLUSIVE_LOCKS_REQUIRED(crit_capture_);
   void InitializeVoiceDetection()
       EXCLUSIVE_LOCKS_REQUIRED(crit_capture_);
+  void InitializeEchoCanceller()
+      EXCLUSIVE_LOCKS_REQUIRED(crit_render_, crit_capture_);
   int InitializeLocked(const ProcessingConfig& config)
       EXCLUSIVE_LOCKS_REQUIRED(crit_render_, crit_capture_);