Remove usage of VoEAudioProcessing from WVoE/MC.

webrtc/voice_engine/voe_base_impl.h

Index: webrtc/voice_engine/voe_base_impl.h
diff --git a/webrtc/voice_engine/voe_base_impl.h b/webrtc/voice_engine/voe_base_impl.h
index a9f06e41323cd33cc8f643164eab9a22ebe8026e..b544c09f9a72bcbe6f68f79b90db6e6830fee7e3 100644
--- a/webrtc/voice_engine/voe_base_impl.h
+++ b/webrtc/voice_engine/voe_base_impl.h
@@ -38,6 +38,9 @@ class VoEBaseImpl : public VoEBase,
   AudioDeviceModule* audio_device_module() override {
     return shared_->audio_device();
   }
+  voe::TransmitMixer* transmit_mixer() override {
+    return shared_->transmit_mixer();
+  }
   int Terminate() override;
 
   int CreateChannel() override;