cros: Arrow key traversal in views.

chrome/browser/resources/chromeos/login/network_dropdown.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 Network drop-down implementation.
  */
 
 cr.define('cr.ui', function() {
   /**
@@ skipping 276 matching lines @@
       });
 
       el.addEventListener('keydown', function f(e) {
         if (this.inFocus && !this.controller.isShown &&
             (e.keyCode == DropDown.KEYCODE_ENTER ||
              e.keyCode == DropDown.KEYCODE_SPACE ||
              e.keyCode == DropDown.KEYCODE_UP ||
              e.keyCode == DropDown.KEYCODE_DOWN)) {
           this.opening = true;
           this.controller.isShown = true;
+          e.stopPropagation();
+          e.preventDefault();
         }
       });
       return el;
     },
 
     /**
      * Handles keydown event from the keyboard.
      * @private
      * @param {!Event} e Keydown event.
      */
     keyDownHandler_: function(e) {
       if (!this.isShown)
         return;
       var selected = this.container.selectedItem;
+      var handled = false;
       switch (e.keyCode) {
         case DropDown.KEYCODE_UP: {
           do {
             selected = selected.previousSibling;
             if (!selected)
               selected = this.container.lastElementChild;
           } while (selected.iid < 0);
           this.container.selectItem(selected, false);
+          handled = true;
           break;
         }
         case DropDown.KEYCODE_DOWN: {
           do {
             selected = selected.nextSibling;
             if (!selected)
               selected = this.container.firstItem;
           } while (selected.iid < 0);
           this.container.selectItem(selected, false);
+          handled = true;
           break;
         }
         case DropDown.KEYCODE_ESC: {
           this.isShown = false;
+          handled = true;
           break;
         }
         case DropDown.KEYCODE_TAB: {
           this.isShown = false;
+          handled = true;
           break;
         }
         case DropDown.KEYCODE_ENTER: {
           if (!this.title_.opening) {
             this.title_.focus();
             this.isShown = false;
             var item =
                 this.title_.controller.container.selectedItem.lastElementChild;
             if (item.iid >= 0 && !item.classList.contains('disabled-item'))
               chrome.send('networkItemChosen', [item.iid]);
           }
+          handled = true;
           break;
         }
       }
+      if (handled) {
+        e.stopPropagation();
+        e.preventDefault();
+      }
       this.title_.opening = false;
     }
   };
 
   /**
    * Updates networks list with the new data.
    * @param {!Object} data Networks list.
    */
   DropDown.updateNetworks = function(data) {
     if (DropDown.activeElementId_)
@@ skipping 43 matching lines @@
    * Refreshes network drop-down. Should be called on language change.
    */
   DropDown.refresh = function() {
     chrome.send('networkDropdownRefresh');
   };
 
   return {
     DropDown: DropDown
   };
 });