Introduce KeepAliveWhilePending to ScriptPromiseResolverWithContext.

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 0465969fe17e86c54995b7ca247752432e2f290c..5f4c88e04d28012f87e4ac150f003fe3a588eafc 100644
--- a/Source/modules/crypto/CryptoResultImpl.h
+++ b/Source/modules/crypto/CryptoResultImpl.h
@@ -40,6 +40,7 @@
 
 namespace WebCore {
 
+class ScriptPromiseResolverWithContext;
 ExceptionCode webCryptoErrorToExceptionCode(blink::WebCryptoErrorType);
 
 // Wrapper around a Promise to notify completion of the crypto operation.
@@ -51,7 +52,7 @@ ExceptionCode webCryptoErrorToExceptionCode(blink::WebCryptoErrorType);
 //  * The CryptoResult interface must only be called from the origin thread.
 //  * addref() and deref() can be called from any thread.
 //  * One of the completeWith***() functions must be called, or the
-//    PromiseState will be leaked until the ExecutionContext is destroyed.
+//    m_resolver will be leaked until the ExecutionContext is destroyed.
 class CryptoResultImpl FINAL : public CryptoResult {
 public:
     ~CryptoResultImpl();
@@ -70,8 +71,7 @@ public:
 private:
     explicit CryptoResultImpl(ScriptState*);
 
-    class PromiseState;
-    WeakPtr<PromiseState> m_promiseState;
+    WeakPtr<ScriptPromiseResolverWithContext> m_resolver;
 };
 
 } // namespace WebCore