CREDENTIAL: Extend FormData opacity to created Request objects

Source/modules/fetch/Request.cpp

Index: Source/modules/fetch/Request.cpp
diff --git a/Source/modules/fetch/Request.cpp b/Source/modules/fetch/Request.cpp
index 830023c354a4805da7e9da4964140a6ab7a96127..f60d832e813ee1e41414f377a55986d34a648bf0 100644
--- a/Source/modules/fetch/Request.cpp
+++ b/Source/modules/fetch/Request.cpp
@@ -263,6 +263,10 @@ Request* Request::createRequestWithRequestOrString(ScriptState* scriptState, Req
     if (temporaryBody)
         r->m_request->setBuffer(temporaryBody);
 
+    // https://w3c.github.io/webappsec/specs/credentialmanagement/#monkey-patching-fetch-2
+    if (init.opaque || (inputRequest && inputRequest->opaque()))
+        r->makeOpaque();
+
     // "34. Set |r|'s MIME type to the result of extracting a MIME type from
     // |r|'s request's header list."
     r->m_request->setMIMEType(r->m_request->headerList()->extractMIMEType());