Made the AudioProcessing class a pure 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 8bb9e08eaddc75c658fdc0d1f1b5a6b8b3f6bf6c..998153deaa2ac7dc2070fe0ca8afb0e2351d9dd3 100644
--- a/webrtc/modules/audio_processing/include/mock_audio_processing.h
+++ b/webrtc/modules/audio_processing/include/mock_audio_processing.h
@@ -259,6 +259,10 @@ class MockAudioProcessing : public AudioProcessing {
                    int64_t max_log_size_bytes));
   MOCK_METHOD2(StartDebugRecording,
                int(FILE* handle, int64_t max_log_size_bytes));
+  MOCK_METHOD1(StartDebugRecording,
+               int (FILE* handle));
+  MOCK_METHOD1(StartDebugRecording,
+               int(rtc::PlatformFile handle));
   MOCK_METHOD0(StopDebugRecording,
       int());
   MOCK_METHOD0(UpdateHistogramsOnCallEnd, void());