Find feature for tracing, at long last.

chrome/browser/resources/tracing/overlay.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 /**
  * @fileoverview Implements an element that is hidden by default, but
  * when shown, dims and (attempts to) disable the main document.
  *
  * You can turn any div into an overlay. Note that while an
@@ skipping 38 matching lines @@
       overlay.oldParent_ = overlay.parentNode;
       this.contentHost.appendChild(overlay);
       this.contentHost.appendChild(this.tabCatcher);
 
       // Show the overlay root.
       this.ownerDocument.body.classList.add('disabled-by-overlay');
       this.visible = true;
 
       // Bring overlay into focus.
       overlay.tabIndex = 0;
-      overlay.focus();
+      var focusElement =
+          overlay.querySelector('button, input, list, select, a');
+      if (!focusElement) {
+        focusElement = overlay;
+      }
+      focusElement.focus();
 
       // Listen to key and focus events to prevent focus from
       // leaving the overlay.
       this.ownerDocument.addEventListener('focusin',
           this.onFocusInBoundToThis_, true);
       overlay.addEventListener('keydown', this.onKeydownBoundToThis_);
     },
 
     /**
      * Clicking outside of the overlay will de-focus the overlay. The
@@ skipping 98 matching lines @@
    * Shows and hides the overlay. Note that while visible == true, the overlay
    * element will be tempoarily reparented to another place in the DOM.
    */
   cr.defineProperty(Overlay, 'visible', cr.PropertyKind.BOOL_ATTR,
       Overlay.prototype.onVisibleChanged_);
 
   return {
     Overlay: Overlay
   };
 });