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

media/base/test_helpers.h

Index: media/base/test_helpers.h
diff --git a/media/base/test_helpers.h b/media/base/test_helpers.h
index 17df67de32c64c71aaad8bbdd2c42793c2df2976..bba60c9af38f3e382e1434ec1d77eda0bf52587e 100644
--- a/media/base/test_helpers.h
+++ b/media/base/test_helpers.h
@@ -6,6 +6,7 @@
 #define MEDIA_BASE_TEST_HELPERS_H_
 
 #include <stddef.h>
+#include <memory>
 
 #include "base/callback.h"
 #include "base/macros.h"
@@ -67,7 +68,7 @@ class WaitableMessageLoopEvent {
   base::MessageLoop* message_loop_;
   bool signaled_;
   PipelineStatus status_;
-  scoped_ptr<base::RunLoop> run_loop_;
+  std::unique_ptr<base::RunLoop> run_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(WaitableMessageLoopEvent);
 };