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

Source/platform/CryptoResult.h

Index: Source/platform/CryptoResult.h
diff --git a/Source/platform/CryptoResult.h b/Source/platform/CryptoResult.h
index 3ccff2e211e705773d5ab873db418b2080aa680b..e97453d3e4b48e0054a751757ab22ea67fee45cd 100644
--- a/Source/platform/CryptoResult.h
+++ b/Source/platform/CryptoResult.h
@@ -37,7 +37,7 @@
 namespace blink {
 
 // Receives notification of completion of the crypto operation.
-class CryptoResult : public ThreadSafeRefCounted<CryptoResult> {
+class CryptoResult : public ThreadSafeRefCountedWillBeGarbageCollectedFinalized<CryptoResult> {
 public:
     virtual ~CryptoResult() { }
 
@@ -53,8 +53,10 @@ public:
     {
         return WebCryptoResult(this);
     }
+
+    DEFINE_INLINE_VIRTUAL_TRACE() { }
 };
 
 } // namespace blink
 
-#endif
+#endif // CryptoResult_h