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

Source/modules/fetch/Body.h

Index: Source/modules/fetch/Body.h
diff --git a/Source/modules/fetch/Body.h b/Source/modules/fetch/Body.h
index 3751b7fe5034bdc8472e59b6d508763ce3de708a..4c988a92d3814f6b0902363fd2e5b1e11584ba22 100644
--- a/Source/modules/fetch/Body.h
+++ b/Source/modules/fetch/Body.h
@@ -56,7 +56,8 @@ public:
     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.