specify realm when creating arraybuffer

fetch.bs

@@ -7274,8 +7274,7 @@ algorithm, given an object that includes {{Body}} <var>object</var> and an algor
 <div algorithm>
 <p>The <dfn method for=Body><code>arrayBuffer()</code></dfn> method steps are to return the result
 of running <a for=Body>consume body</a> with <a>this</a> and the following step given a
-<a for=/>byte sequence</a> <var>bytes</var>: return a new {{ArrayBuffer}} whose contents are
-<var>bytes</var>.
+<a for=/>byte sequence</a> <var>bytes</var>: return the result of [=ArrayBuffer/creating=] an {{ArrayBuffer}} from <var>bytes</var> in <a>this</a>'s <a>relevant realm</a>.
 
 <p class="note">The above method can reject with a {{RangeError}}.
 </div>
@@ -7291,7 +7290,7 @@ and whose {{Blob/type}} attribute is the result of <a for=Body>get the MIME type
 
 <div algorithm>
 <p>The <dfn method for=Body><code>formData()</code></dfn> method steps are to return the result of
-running <a for=Body>consume body</a> with <a>this</a> and the following step given a
+running <a for=Body>consume body</a> with <a>this</a> and the following steps given a
 <a for=/>byte sequence</a> <var>bytes</var>:
 
 <ol>