Add a limited size buffer for streaming upload in HTTP request.

fetch.bs

@@ -5063,21 +5063,20 @@ optional boolean <var>forceNewConnection</var> (default false), run these steps:
 
      <li>
       <p>If <var>request</var>'s <a for=request>body</a> is non-null, and <var>request</var>'s
-      <a for=request>body</a>'s <a for=body>source</a> is null, the user agent may have a buffer up
-      to 64 kibibytes and store a part of <var>request</var>'s <a for=request>body</a> to the buffer.
-      If the user agent reads from <var>request</var>'s <a for=request>body</a> beyond the buffer
-      size and the user agent is required to resend <var>request</var>, return a
-      <a>network error</a>.
+      <a for=request>body</a>'s <a for=body>source</a> is null, then the user agent may have a
+      buffer up to 64 kibibytes and store a part of <var>request</var>'s <a for=request>body</a> in
+      the buffer. If the user agent reads from <var>request</var>'s <a for=request>body</a> beyond
+      the buffer size, then <var>request</var> is no longer eligible for resending.
 
-      <div class="note no-backref">
+      <div class=note>
        <p>The resending is needed when the connection is timed out, for example.
 
        <p>The buffer is not needed when <var>request</var>'s <a for=request>body</a>'s
-       <a for=body>source</a> is non-null, because the <a for=request>body</a> can be recreated
-       from it.
+       <a for=body>source</a> is non-null, because <var>request</var>'s <a for=request>body</a> can
+       be recreated from it.
 
        <p>When <var>request</var>'s <a for=request>body</a>'s <a for=body>source</a> is null, it
-       means <a for=request>body</a> is created from {{ReadableStream}}, which means
+       means <a for=request>body</a> is created from a {{ReadableStream}} object, which means
        <a for=request>body</a> cannot be recreated and that is why the buffer is needed.
       </div>