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

LayoutTests/http/tests/fetch/script-tests/request.js

Index: LayoutTests/http/tests/fetch/script-tests/request.js
diff --git a/LayoutTests/http/tests/fetch/script-tests/request.js b/LayoutTests/http/tests/fetch/script-tests/request.js
index 1a913871797d3c227f9bc910ce419bbdc4b74a36..7e16329c30e3999b4f9d8d6f590641ff4e42c23e 100644
--- a/LayoutTests/http/tests/fetch/script-tests/request.js
+++ b/LayoutTests/http/tests/fetch/script-tests/request.js
@@ -473,14 +473,16 @@ promise_test(function() {
                   'Headers of cloned request should not change when ' +
                   'original request headers are changed.');
 
-    return req.text()
-      .then(function(text) {
-          assert_equals(text, 'Test Blob', 'Body of request should match.');
-          return req2.text();
-        })
-      .then(function(text) {
-          assert_equals(text, 'Test Blob', 'Cloned request body should match.');
-        });
+    return req.text().then(function(text) {
+        assert_equals(text, 'Test Blob', 'Body of request should match.');
+        return req2.text();
+      }).then(function(text) {
+        assert_equals(text, 'Test Blob', 'Cloned request body should match.');
+        return Promise.all([req.text(), req2.text()]);
+      }).then(function(texts) {
+        assert_equals(texts[0], '', 'The body is consumed.');
+        assert_equals(texts[1], '', 'The body is consumed.');
+      });
   }, 'Test clone behavior with loading content from Request.');
 
 async_test(function(t) {