Replace scoped_ptr with std::unique_ptr in //media/base.

media/base/text_track.h

Index: media/base/text_track.h
diff --git a/media/base/text_track.h b/media/base/text_track.h
index 0e04a0eb46dab94db2290c73df6cf4b3f6293492..03e52cf67cb8fed3b850ce90affbb336ecd928b5 100644
--- a/media/base/text_track.h
+++ b/media/base/text_track.h
@@ -5,10 +5,10 @@
 #ifndef MEDIA_BASE_TEXT_TRACK_H_
 #define MEDIA_BASE_TEXT_TRACK_H_
 
+#include <memory>
 #include <string>
 
 #include "base/callback.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 
 namespace media {
@@ -25,12 +25,10 @@ class TextTrack {
                             const std::string& settings) = 0;
 };
 
-typedef base::Callback<void
-    (scoped_ptr<TextTrack>)> AddTextTrackDoneCB;
+using AddTextTrackDoneCB = base::Callback<void(std::unique_ptr<TextTrack>)>;
 
-typedef base::Callback<void
-    (const TextTrackConfig& config,
-     const AddTextTrackDoneCB& done_cb)> AddTextTrackCB;
+using AddTextTrackCB = base::Callback<void(const TextTrackConfig& config,
+                                           const AddTextTrackDoneCB& done_cb)>;
 
 }  // namespace media