Remove use of WebCrypto digestSynchronous in Blink.

Source/modules/websockets/WebSocketHandshake.cpp

Index: Source/modules/websockets/WebSocketHandshake.cpp
diff --git a/Source/modules/websockets/WebSocketHandshake.cpp b/Source/modules/websockets/WebSocketHandshake.cpp
index 8def260211d99ec01d31d12fbaff82a571d8c784..f5afeeda620fc213f27fe68ace8c84e9ae6cecc1 100644
--- a/Source/modules/websockets/WebSocketHandshake.cpp
+++ b/Source/modules/websockets/WebSocketHandshake.cpp
@@ -126,7 +126,8 @@ String WebSocketHandshake::getExpectedWebSocketAccept(const String& secWebSocket
     digestable.append(webSocketKeyGUID, strlen(webSocketKeyGUID));
     CString digestableCString = digestable.toString().utf8();
     DigestValue digest;
-    computeDigest(HashAlgorithmSha1, digestableCString.data(), digestableCString.length(), digest);
+    bool digestSuccess = computeDigest(HashAlgorithmSha1, digestableCString.data(), digestableCString.length(), digest);
+    RELEASE_ASSERT(digestSuccess);
 
     return base64Encode(reinterpret_cast<const char*>(digest.data()), sha1HashSize);
 }