Pressing 'Delete' key in bookmark manager's search box deletes bookmark.

chrome/browser/resources/bookmark_manager/js/main.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.
 
 (function() {
 /** @const */ var BookmarkList = bmm.BookmarkList;
 /** @const */ var BookmarkTree = bmm.BookmarkTree;
 /** @const */ var Command = cr.ui.Command;
 /** @const */ var LinkKind = cr.LinkKind;
 /** @const */ var ListItem = cr.ui.ListItem;
@@ skipping 478 matching lines @@
       break;
 
     case 'undo-command':
       // If the search box is active, pass the undo command through
       // (fixes http://crbug.com/278112). Otherwise, because
       // the global undo command has no visible UI, always enable it, and
       // just make it a no-op if undo is not possible.
       e.canExecute = e.currentTarget.activeElement !== $('term');
       break;
 
+    case 'delete-command':
+      // If the search box is active, pass the delete command
+      e.canExecute = e.currentTarget.activeElement !== $('term');

[Bernhard Bauer, 2015/04/15 12:51:16]

Right. This means however that we will always make a decision whether the delete
command can execute. If the search field is not active, we want to delegate that
decision to canExecuteForList() and canExecuteForTree() below, so you want to
set canExecute (and break) only if the search field is active.

(BTW, this is why I suggested moving this code to a separate handler on the
search field: it removes the necessity of the activeElement check, and it avoids
conflating different reasons for allowing a command to execute or not, which is
what happens for the 'undo-command' case above.)

+      break;
+
     default:
       canExecuteForList(e);
       if (!e.defaultPrevented)
         canExecuteForTree(e);
       break;
   }
 }
 
 /**
  * Helper function for handling canExecute for the list and the tree.
@@ skipping 997 matching lines @@
 
   cr.ui.FocusOutlineManager.forDocument(document);
   initializeSplitter();
   bmm.addBookmarkModelListeners();
   dnd.init(selectItemsAfterUserAction);
   bmm.tree.reload();
 }
 
 initializeBookmarkManager();
 })();