Update the offscreen transfer steps, and clarify lang rules.

source

@@ -66759,7 +66759,8 @@ worker.postMessage(offscreenCanvas, [offscreenCanvas]);</code></pre>
     </ol>
    </li>
    <li><p>Otherwise, the <span data-x="concept-CanvasTextDrawingStyles-font-language">font
-   language</span> is the value.</p></li>
+   language</span> is the value, with the semantics of the global <code
+   data-x="attr-lang">lang</code> attribute.</p></li>
   </ol>
 
   <p>When the object implementing the <code>CanvasTextDrawingStyles</code> interface is created,
@@ -71409,11 +71410,18 @@ interface <dfn interface>OffscreenCanvas</dfn> : <span>EventTarget</span> {
    <li><p>Let <var>width</var> and <var>height</var> be the dimensions of <var>value</var>'s <span
    data-x="offscreencanvas-bitmap">bitmap</span>.</p></li>
 
+   <li><p>Let <var>language</var> and <var>direction</var> be the values of <var>value</var>'s
+   <span data-x="offscreencanvas-inherited-lang">inherited language</span> and
+   <span data-x="offscreencanvas-inherited-direction">inherited direction</span>.</p></li>
+
    <li><p>Unset <var>value</var>'s <span data-x="offscreencanvas-bitmap">bitmap</span>.</p></li>
 
    <li><p>Set <var>dataHolder</var>.[[Width]] to <var>width</var> and
    <var>dataHolder</var>.[[Height]] to <var>height</var>.</p></li>
 
+   <li><p>Set <var>dataHolder</var>.[[Language]] to <var>language</var> and
+   <var>dataHolder</var>.[[Direction]] to <var>direction</var>.</p></li>
+
    <li><p>Set <var>dataHolder</var>.[[PlaceholderCanvas]] to be a weak reference to
    <var>value</var>'s <span data-x="offscreencanvas-placeholder">placeholder <code>canvas</code>
    element</span>, if <var>value</var> has one, or null if it does not.</p></li>
@@ -71427,6 +71435,11 @@ interface <dfn interface>OffscreenCanvas</dfn> : <span>EventTarget</span> {
    rectangular array of <span>transparent black</span> pixels with width given by
    <var>dataHolder</var>.[[Width]] and height given by <var>dataHolder</var>.[[Height]].</p></li>
 
+   <li><p>Set <var>value</var>'s <span data-x="offscreencanvas-inherited-lang">inherited
+   language</span> to <var>dataHolder</var>.[[Language]] and <span
+   data-x="offscreencanvas-inherited-direction">inherited direction</span> to
+   <var>dataHolder</var>.[[Direction]].</p></li>
+
    <li><p>If <var>dataHolder</var>.[[PlaceholderCanvas]] is not null, set <var>value</var>'s <span
    data-x="offscreencanvas-placeholder">placeholder <code>canvas</code> element</span> to
    <var>dataHolder</var>.[[PlaceholderCanvas]] (while maintaining the weak reference