CREDENTIAL: Extend FormData opacity to created Request objects

Source/modules/fetch/Body.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef Body_h
 #define Body_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/dom/ActiveDOMObject.h"
@@ skipping 32 matching lines @@
     void setBodyPassed() { m_bodyPassed = true; }
 
     // ActiveDOMObject override.
     bool hasPendingActivity() const override;
 
     DEFINE_INLINE_VIRTUAL_TRACE()
     {
         ActiveDOMObject::trace(visitor);
     }
 
+    void makeOpaque() { m_opaque = true; }
+    bool opaque() const { return m_opaque; }
+
 private:
     virtual String mimeType() const = 0;
 
     bool m_bodyPassed;
+    bool m_opaque;
 };
 
 } // namespace blink
 
 #endif // Body_h