Remove OwnPtr from Blink.

third_party/WebKit/Source/modules/mediasession/MediaSession.h

Index: third_party/WebKit/Source/modules/mediasession/MediaSession.h
diff --git a/third_party/WebKit/Source/modules/mediasession/MediaSession.h b/third_party/WebKit/Source/modules/mediasession/MediaSession.h
index 8501a3bd4a7ce46a06686c6ab2c6060c50bb28b9..07c250043c9f700083439d3df9c3b3dbf94fbb80 100644
--- a/third_party/WebKit/Source/modules/mediasession/MediaSession.h
+++ b/third_party/WebKit/Source/modules/mediasession/MediaSession.h
@@ -10,7 +10,7 @@
 #include "modules/ModulesExport.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/modules/mediasession/WebMediaSession.h"
-#include "wtf/OwnPtr.h"
+#include <memory>
 
 namespace blink {
 
@@ -37,9 +37,9 @@ public:
 private:
     friend class MediaSessionTest;
 
-    explicit MediaSession(PassOwnPtr<WebMediaSession>);
+    explicit MediaSession(std::unique_ptr<WebMediaSession>);
 
-    OwnPtr<WebMediaSession> m_webMediaSession;
+    std::unique_ptr<WebMediaSession> m_webMediaSession;
     Member<MediaMetadata> m_metadata;
 };