Prerender need to be on the Oilpan heap.

third_party/WebKit/Source/platform/PrerenderClient.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 15 matching lines @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
 
 #ifndef PrerenderClient_h
 #define PrerenderClient_h
 
 #include "platform/PlatformExport.h"
+#include "platform/heap/Handle.h"
 
 namespace blink {
 
-class PLATFORM_EXPORT PrerenderClient {
+class PLATFORM_EXPORT PrerenderClient : public GarbageCollectedMixin {
 public:
     virtual ~PrerenderClient() { }
 
     virtual void didStartPrerender() = 0;
     virtual void didStopPrerender() = 0;
     virtual void didSendLoadForPrerender() = 0;
     virtual void didSendDOMContentLoadedForPrerender() = 0;
+
+    DEFINE_INLINE_VIRTUAL_TRACE() { }
 };
 
 } // namespace blink
 
 #endif