Reliably cancel in-progress CryptoResult(Impl) upon shutdown.

Source/modules/crypto/CryptoResultImpl.h

Index: Source/modules/crypto/CryptoResultImpl.h
diff --git a/Source/modules/crypto/CryptoResultImpl.h b/Source/modules/crypto/CryptoResultImpl.h
index b6cb6e90126c8290fdfbbd3a2172afc230868247..311f9c674e2c8e6b609331396fe76adc3729b704 100644
--- a/Source/modules/crypto/CryptoResultImpl.h
+++ b/Source/modules/crypto/CryptoResultImpl.h
@@ -37,10 +37,10 @@
 #include "platform/CryptoResult.h"
 #include "public/platform/WebCrypto.h"
 #include "wtf/Forward.h"
+#include "wtf/ThreadingPrimitives.h"
 
 namespace blink {
 
-class ScriptPromiseResolver;
 MODULES_EXPORT ExceptionCode webCryptoErrorToExceptionCode(WebCryptoErrorType);
 
 // Wrapper around a Promise to notify completion of the crypto operation.
@@ -50,15 +50,16 @@ MODULES_EXPORT ExceptionCode webCryptoErrorToExceptionCode(WebCryptoErrorType);
 //
 //  * At creation time there must be an active ExecutionContext.
 //  * The CryptoResult interface must only be called from the origin thread.
-//  * ref(), deref(), cancelled() and cancel() can be called from any thread.
+//  * cancel() can only be called from the origin thread.
+//  * ref(), deref() can be called from any thread.
 //  * One of the completeWith***() functions must be called, or the
 //    m_resolver will be leaked until the ExecutionContext is destroyed.
 class CryptoResultImpl final : public CryptoResult {
 public:
-    ~CryptoResultImpl();
-
     static PassRefPtrWillBeRawPtr<CryptoResultImpl> create(ScriptState*);
 
+    ~CryptoResultImpl();
+
     void completeWithError(WebCryptoErrorType, const WebString&) override;
     void completeWithBuffer(const void* bytes, unsigned bytesSize) override;
     void completeWithJson(const char* utf8Data, unsigned length) override;
@@ -71,19 +72,24 @@ public:
     // ScriptPromise.
     ScriptPromise promise();
 
+    WebCryptoResult result()
+    {
+        return WebCryptoResult(this);
+    }
+
+    DECLARE_VIRTUAL_TRACE();
+
 private:
     class Resolver;
     explicit CryptoResultImpl(ScriptState*);
 
-    void clearResolver();
     void cancel();
+    void clearResolver();
 
-    // FIXME: ScriptPromiseResolver should not be exported.
-    // Instead, use ScriptPromise.
-    ScriptPromiseResolver* m_resolver;
+    RawPtrWillBeMember<Resolver> m_resolver;
     volatile int m_cancelled;
 };
 
 } // namespace blink
 
-#endif
+#endif // CryptoResultImpl_h