Pass in Content-Encoding to resource-timing

fetch.bs

@@ -369,6 +369,8 @@ following <a for=struct>items</a>: [[RESOURCE-TIMING]] [[NAVIGATION-TIMING]]
  <dd>A number.
  <dt><dfn export for="response body info">content type</dfn> (default the empty string)
  <dd>An <a for=/>ASCII string</a>.
+ <dt><dfn export for="response body info">content encoding</dfn> (default the empty string)
+ <dd>An <a for=/>ASCII string</a>.
 </dl>
 
 <div algorithm>
@@ -4816,7 +4818,17 @@ steps:
        <li><p>If <var>mimeType</var> is not failure, then set <var>bodyInfo</var>'s
        <a for="response body info">content type</a> to the result of
        <a>minimizing a supported MIME type</a> given <var>mimeType</var>.
-      </ol>
+
+       <li><p>Let <var>contentEncoding</var> be the result of
+       <a for="header list">extracting a MIME type</a> from <var>response</var>'s
+       <a for=response>header list</a>.
+
+       <li><p>Let <var>contentEncodings</var> be the result of <a>extracting header list values</a> given
+       `<code>Content-Encoding</code>` and <var>response</var>'s <a for=response>header list</a>.
+
+       <li><p>If <var>contentEncoding</var> is not failure, then set <var>bodyInfo</var>'s
+       <a for="response body info">content encoding</a> to <var>contentEncoding</var>.
+     </ol>
 
      <li><p>If <var>fetchParams</var>'s <a for="fetch params">request</a>'s
      <a for=request>initiator type</a> is non-null, then <a for=/>mark resource timing</a> given