Have ScriptPromiseResolver on the Oilpan heap always.

public/platform/WebCrypto.h

 /*
  * Copyright (C) 2013 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 77 matching lines @@
     BLINK_PLATFORM_EXPORT void completeWithJson(const char* utf8Data, unsigned length);
     BLINK_PLATFORM_EXPORT void completeWithBoolean(bool);
     BLINK_PLATFORM_EXPORT void completeWithKey(const WebCryptoKey&);
     BLINK_PLATFORM_EXPORT void completeWithKeyPair(const WebCryptoKey& publicKey, const WebCryptoKey& privateKey);
 
     // Returns true if the underlying operation was cancelled.
     // This method can be called from any thread.
     BLINK_PLATFORM_EXPORT bool cancelled() const;
 
 #if INSIDE_BLINK
-    BLINK_PLATFORM_EXPORT WebCryptoResult(const PassRefPtrWillBeRawPtr<CryptoResult>&, const PassRefPtr<CryptoResultCancel>&);
+    BLINK_PLATFORM_EXPORT WebCryptoResult(CryptoResult*, const PassRefPtr<CryptoResultCancel>&);
 #endif
 
 private:
     BLINK_PLATFORM_EXPORT void reset();
     BLINK_PLATFORM_EXPORT void assign(const WebCryptoResult&);
 
     WebPrivatePtr<CryptoResult, WebPrivatePtrDestructionCrossThread> m_impl;
     WebPrivatePtr<CryptoResultCancel, WebPrivatePtrDestructionCrossThread> m_cancel;
 };
 
@@ skipping 159 matching lines @@
     // Returns true on success.
     virtual bool serializeKeyForClone(const WebCryptoKey&, WebVector<unsigned char>&) { return false; }
 
 protected:
     virtual ~WebCrypto() { }
 };
 
 } // namespace blink
 
 #endif // WebCrypto_h