Make GetConfig() part of the AudioProcessing interface

webrtc/modules/audio_processing/include/mock_audio_processing.h

Index: webrtc/modules/audio_processing/include/mock_audio_processing.h
diff --git a/webrtc/modules/audio_processing/include/mock_audio_processing.h b/webrtc/modules/audio_processing/include/mock_audio_processing.h
index b5a1fa4a8851329111db743bbacf77d1c33a0f89..4bda0bd090f213f05358ab2c91d2c079aff5f562 100644
--- a/webrtc/modules/audio_processing/include/mock_audio_processing.h
+++ b/webrtc/modules/audio_processing/include/mock_audio_processing.h
@@ -206,6 +206,8 @@ class MockAudioProcessing : public AudioProcessing {
     return voice_detection_.get();
   }
 
+  MOCK_CONST_METHOD0(GetConfig, AudioProcessing::Config());
+
  private:
   std::unique_ptr<MockEchoCancellation> echo_cancellation_;
   std::unique_ptr<MockEchoControlMobile> echo_control_mobile_;