[Fetch] Body consume function should not set bodyUsed flag.

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/ScriptPromiseResolver.h"
 #include "bindings/core/v8/ScriptWrappable.h"
@@ skipping 38 matching lines @@
     ScriptPromise arrayBuffer(ScriptState*);
     ScriptPromise blob(ScriptState*);
     ScriptPromise formData(ScriptState*);
     ScriptPromise json(ScriptState*);
     ScriptPromise text(ScriptState*);
     ReadableByteStream* body();
 
     bool bodyUsed() const;
     void lockBody(LockBodyOption = LockBodyOptionNone);
 
-    bool streamAccessed() const;
+    // Returns true if the body stream is (possibly partially) consumed.
+    bool isBodyConsumed() const;
     void refreshBody();
 
     // Creates a new BodyStreamBuffer to drain the data from the ReadableStream.
     BodyStreamBuffer* createDrainingStream();
 
     // ActiveDOMObject override.
     virtual void stop() override;
     virtual bool hasPendingActivity() const override;
 
     DECLARE_VIRTUAL_TRACE();
@@ skipping 32 matching lines @@
     bool m_bodyUsed;
     ResponseType m_responseType;
     RefPtrWillBeMember<ScriptPromiseResolver> m_resolver;
     Member<ReadableStreamSource> m_streamSource;
     Member<ReadableByteStream> m_stream;
 };
 
 } // namespace blink
 
 #endif // Body_h