Preparational work for an upcoming addition of a threadchecking scheme for APM

webrtc/modules/audio_processing/audio_processing_impl.h

Index: webrtc/modules/audio_processing/audio_processing_impl.h
diff --git a/webrtc/modules/audio_processing/audio_processing_impl.h b/webrtc/modules/audio_processing/audio_processing_impl.h
index 72dfbf419b27ee264d870c22ef5a71330ae4d7e0..f8d9f7c2ba5d4bf1ee8f2be8b684728597e69048 100644
--- a/webrtc/modules/audio_processing/audio_processing_impl.h
+++ b/webrtc/modules/audio_processing/audio_processing_impl.h
@@ -17,6 +17,7 @@
 
 #include "webrtc/base/scoped_ptr.h"
 #include "webrtc/base/thread_annotations.h"
+#include "webrtc/base/thread_checker.h"
 #include "webrtc/modules/audio_processing/include/audio_processing.h"
 
 namespace webrtc {
@@ -154,6 +155,9 @@ class AudioProcessingImpl : public AudioProcessing {
 
   std::list<ProcessingComponent*> component_list_;
   CriticalSectionWrapper* crit_;
+  rtc::ThreadChecker render_thread_checker_;
+  rtc::ThreadChecker capture_thread_checker_;
+  rtc::ThreadChecker signal_thread_checker_;
   rtc::scoped_ptr<AudioBuffer> render_audio_;
   rtc::scoped_ptr<AudioBuffer> capture_audio_;
   rtc::scoped_ptr<AudioConverter> render_converter_;