Added aria-hidden attribute to elements obscured behind an overlay to aid screen readers.

chrome/browser/resources/options2/options_page.js

Index: chrome/browser/resources/options2/options_page.js
diff --git a/chrome/browser/resources/options2/options_page.js b/chrome/browser/resources/options2/options_page.js
index b8b6d0f33a4da803a92d2a548157947fae195d4c..c94abfd3d68b17f14ee38e5bc8281330213327ee 100644
--- a/chrome/browser/resources/options2/options_page.js
+++ b/chrome/browser/resources/options2/options_page.js
@@ -234,6 +234,12 @@ cr.define('options', function() {
     if (!overlay || !overlay.canShowPage())
       return false;
 
+    // The current topmost page will soon be obscured behind the new overlay
+    // to be shown. To prevent screen readers from reading this "hidden"
+    // information, enable the aria-hidden attribute on this page.
+    var topmostPage = this.getTopmostVisiblePage();

[Evan Stade, 2012/05/09 22:37:37]

seems like this might do the wrong thing in certain cases, such as if you called
showOverlay twice on the same overlay (which can probably happen). Or if you
call showOverlay while dialog A is showing, then call showOverlay on dialog B,
then showOverlay on A again. A will still have aria-hidden on true. 

[Kyle Horimoto, 2012/05/10 22:18:46]

Done.

+    topmostPage.pageDiv.setAttribute('aria-hidden', true);
+
     if ((!rootPage || !rootPage.sticky) && overlay.parentPage)
       this.showPageByName(overlay.parentPage.name, false);
 
@@ -286,6 +292,11 @@ cr.define('options', function() {
 
     if (overlay.didClosePage) overlay.didClosePage();
     this.updateHistoryState_(false, {ignoreHash: true});
+
+    // Since there is now a new topmost page, disable its aria-hidden attribute
+    // to allow screen readers to read its contents.
+    var topmostPage = this.getTopmostVisiblePage();
+    topmostPage.pageDiv.removeAttribute('aria-hidden');
   };
 
   /**