Deprecate NonThreadSafe in content/renderer/media in favor of SequenceChecker.

content/renderer/media/rtc_dtmf_sender_handler.h

Index: content/renderer/media/rtc_dtmf_sender_handler.h
diff --git a/content/renderer/media/rtc_dtmf_sender_handler.h b/content/renderer/media/rtc_dtmf_sender_handler.h
index d46ef2c61a2e7039409f472344c15fe284a193ec..fe9923a009a5d9f40756094c270368110952cd0c 100644
--- a/content/renderer/media/rtc_dtmf_sender_handler.h
+++ b/content/renderer/media/rtc_dtmf_sender_handler.h
@@ -10,7 +10,7 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/platform/WebRTCDTMFSenderHandler.h"
 #include "third_party/WebKit/public/platform/WebRTCDTMFSenderHandlerClient.h"
@@ -25,8 +25,7 @@ namespace content {
 // Callbacks to the webrtc::DtmfSenderObserverInterface implementation also
 // occur on the main render thread.
 class CONTENT_EXPORT RtcDtmfSenderHandler
-    : NON_EXPORTED_BASE(public blink::WebRTCDTMFSenderHandler),
-      NON_EXPORTED_BASE(public base::NonThreadSafe) {
+    : NON_EXPORTED_BASE(public blink::WebRTCDTMFSenderHandler) {
  public:
   explicit RtcDtmfSenderHandler(webrtc::DtmfSenderInterface* dtmf_sender);
   ~RtcDtmfSenderHandler() override;
@@ -47,6 +46,8 @@ class CONTENT_EXPORT RtcDtmfSenderHandler
   class Observer;
   scoped_refptr<Observer> observer_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   // |weak_factory_| must be the last member.
   base::WeakPtrFactory<RtcDtmfSenderHandler> weak_factory_;
 
@@ -56,4 +57,3 @@ class CONTENT_EXPORT RtcDtmfSenderHandler
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_RTC_DTMF_SENDER_HANDLER_H_
-