Remove [PrimaryGlobal]

Helps with whatwg/webidl#365.

Tests at web-platform-tests/wpt#8585.

Author: annevk

source

@@ -78016,7 +78016,9 @@ console.assert(iframeWindow.frameElement === null);
 
   <h3 split-filename="window-object">The <code>Window</code> object</h3>
 
-  <pre class="idl">[PrimaryGlobal, LegacyUnenumerableNamedProperties] <!-- Exposed=Window is implied because it's the primary global -->
+  <pre class="idl">[Global=Window,
+ Exposed=Window,
+ LegacyUnenumerableNamedProperties]
 interface <dfn data-export="" data-dfn-type="interface">Window</dfn> : <span>EventTarget</span> {
   // the current browsing context
   [Unforgeable] readonly attribute <span>WindowProxy</span> <span data-x="dom-window">window</span>;