Move mediastream module to oilpan transition types

Source/modules/mediastream/RTCSessionDescription.h

Index: Source/modules/mediastream/RTCSessionDescription.h
diff --git a/Source/modules/mediastream/RTCSessionDescription.h b/Source/modules/mediastream/RTCSessionDescription.h
index 8e87f89e731cc967ea90e4bc2e00bcb6fdb957ed..d2b06a348a45e925b42bb746e33c2b4ce1f8c673 100644
--- a/Source/modules/mediastream/RTCSessionDescription.h
+++ b/Source/modules/mediastream/RTCSessionDescription.h
@@ -42,10 +42,11 @@ namespace WebCore {
 class Dictionary;
 class ExceptionState;
 
-class RTCSessionDescription FINAL : public RefCounted<RTCSessionDescription>, public ScriptWrappable {
+class RTCSessionDescription FINAL : public RefCountedWillBeGarbageCollectedFinalized<RTCSessionDescription>, public ScriptWrappable {
+    DECLARE_GC_INFO;
 public:
-    static PassRefPtr<RTCSessionDescription> create(const Dictionary&, ExceptionState&);
-    static PassRefPtr<RTCSessionDescription> create(blink::WebRTCSessionDescription);
+    static PassRefPtrWillBeRawPtr<RTCSessionDescription> create(const Dictionary&, ExceptionState&);
+    static PassRefPtrWillBeRawPtr<RTCSessionDescription> create(blink::WebRTCSessionDescription);
 
     String type();
     void setType(const String&, ExceptionState&);
@@ -55,6 +56,8 @@ public:
 
     blink::WebRTCSessionDescription webSessionDescription();
 
+    void trace(Visitor*) { }
+
 private:
     explicit RTCSessionDescription(blink::WebRTCSessionDescription);