[Local NTP] Add role="presentation" on the New Tab Page iframe.

chrome/browser/resources/local_ntp/local_ntp.js

Index: chrome/browser/resources/local_ntp/local_ntp.js
diff --git a/chrome/browser/resources/local_ntp/local_ntp.js b/chrome/browser/resources/local_ntp/local_ntp.js
index da790a12feebf2ca0b58047e2ef1c37c7e654a22..cab412fc033123fa9414d58046f1d1cf0881b809 100644
--- a/chrome/browser/resources/local_ntp/local_ntp.js
+++ b/chrome/browser/resources/local_ntp/local_ntp.js
@@ -698,6 +698,9 @@ function createTile(page, position) {
   // link element (which also has a tabindex).
   titleElem.tabIndex = '0';
 
+  // Make the iframe invisible to screen readers.

[dmazzoni, 2015/01/29 18:48:44]

Let's reword this slightly. It implies that we're hiding the whole frame and its
contents. How about something like:

// Make the iframe presentational for accessibility so screen readers perceive
the iframe content as just part of the same page.

[Mathieu, 2015/01/29 18:53:35]

Done.

+  titleElem.setAttribute('role', 'presentation');
+
   // Why iframes have IDs:
   //
   // On navigating back to the NTP we see several onmostvisitedchange() events
@@ -729,7 +732,9 @@ function createTile(page, position) {
   // The iframe which renders either a thumbnail or domain element.
   var thumbnailElem = document.createElement('iframe');
   thumbnailElem.tabIndex = '-1';
+  // Make the iframe invisible to screen readers.
   thumbnailElem.setAttribute('aria-hidden', 'true');
+  titleElem.setAttribute('role', 'presentation');

[dmazzoni, 2015/01/29 18:48:43]

This one is unnecessary, the iframe is already invisible to screen readers due
to aria-hidden

[Mathieu, 2015/01/29 18:53:35]

Done.

   // Keep this ID here. See comment above.
   thumbnailElem.id = 'thumb-' + rid;
   thumbnailElem.className = CLASSES.THUMBNAIL;