Deprecate NonThreadSafe in content/browser/streams in favor of SequenceChecker.

content/browser/streams/stream_registry.h

Index: content/browser/streams/stream_registry.h
diff --git a/content/browser/streams/stream_registry.h b/content/browser/streams/stream_registry.h
index c7b31ab779257749a452d5ad5655921559dface2..6ef17b1b65045e7ebc12a60df7cfe6d09f01af9d 100644
--- a/content/browser/streams/stream_registry.h
+++ b/content/browser/streams/stream_registry.h
@@ -12,7 +12,7 @@
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "content/browser/streams/stream_register_observer.h"
 #include "content/common/content_export.h"
 #include "url/gurl.h"
@@ -22,7 +22,7 @@ namespace content {
 class Stream;
 
 // Maintains a mapping of blob: URLs to active streams.
-class CONTENT_EXPORT StreamRegistry : public base::NonThreadSafe {
+class CONTENT_EXPORT StreamRegistry {
  public:
   StreamRegistry();
   virtual ~StreamRegistry();
@@ -74,6 +74,8 @@ class CONTENT_EXPORT StreamRegistry : public base::NonThreadSafe {
   // with this registry.
   size_t max_memory_usage_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(StreamRegistry);
 };