Swap use of CriticalSectionWrapper with rtc::CriticalSection in voice_engine/

webrtc/voice_engine/dtmf_inband.h

Index: webrtc/voice_engine/dtmf_inband.h
diff --git a/webrtc/voice_engine/dtmf_inband.h b/webrtc/voice_engine/dtmf_inband.h
index eb045c925d5872b164814711ba9a0f8681b3d5f8..c2e2b2bcc804163e52106174b35a972178bcd796 100644
--- a/webrtc/voice_engine/dtmf_inband.h
+++ b/webrtc/voice_engine/dtmf_inband.h
@@ -13,9 +13,9 @@
 
 #include "webrtc/typedefs.h"
 #include "webrtc/voice_engine/voice_engine_defines.h"
+#include "webrtc/base/criticalsection.h"
 
 namespace webrtc {
-class CriticalSectionWrapper;
 
 class DtmfInband
 {
@@ -67,7 +67,7 @@ private:
                                    int16_t length);
 
 private:
-    CriticalSectionWrapper& _critSect;
+    mutable rtc::CriticalSection _critSect;
     int32_t _id;
     uint16_t _outputFrequencyHz;  // {8000, 16000, 32000}
     int16_t _oldOutputLow[2];     // Data needed for oscillator model