[Multi Profile] Double-clicking an item in the user list should edit that profile.

chrome/browser/resources/shared/js/cr/ui/list.js

Index: chrome/browser/resources/shared/js/cr/ui/list.js
diff --git a/chrome/browser/resources/shared/js/cr/ui/list.js b/chrome/browser/resources/shared/js/cr/ui/list.js
index 0357c2f534f173fc7edb1ee9f33672b260602a9e..291d5ff81284abd6ca37eb45410e12437b6bb14e 100644
--- a/chrome/browser/resources/shared/js/cr/ui/list.js
+++ b/chrome/browser/resources/shared/js/cr/ui/list.js
@@ -348,6 +348,7 @@ cr.define('cr.ui', function() {
       var length = this.dataModel ? this.dataModel.length : 0;
       this.selectionModel = new ListSelectionModel(length);
 
+      this.addEventListener('dblclick', this.handleDoubleClick_);
       this.addEventListener('mousedown', this.handleMouseDownUp_);
       this.addEventListener('mouseup', this.handleMouseDownUp_);
       this.addEventListener('keydown', this.handleKeyDown);
@@ -390,6 +391,20 @@ cr.define('cr.ui', function() {
     },
 
     /**
+     * Callback for the double click event.
+     * @param {Event} e The mouse event object.
+     * @private
+     */
+    handleDoubleClick_: function(e) {
+      if (this.disabled)
+        return;
+
+      var target = this.getListItemAncestor(e.target);
+      if (target)
+        this.activateItemAtIndex(this.getIndexOfListItem(target));
+    },
+
+    /**
      * Callback for mousedown and mouseup events.
      * @param {Event} e The mouse event object.
      * @private
@@ -930,6 +945,14 @@ cr.define('cr.ui', function() {
         this.redraw();
       }
     },
+
+    /**
+     * Called when a list item is activated, currently only by a double click
+     * event.
+     * @param {number} index The index of the activated item.
+     */
+    activateItemAtIndex: function(index) {
+    },
   };
 
   cr.defineProperty(List, 'disabled', cr.PropertyKind.BOOL_ATTR);