[MD Bookmarks] Deselect items when clicking outside the bookmark card.

chrome/test/data/webui/md_bookmarks/reducers_test.js

 // Copyright 2017 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.
 
 suite('selection state', function() {
   var state;
   var action;
 
   function select(items, anchor, add) {
     return {
@@ skipping 60 matching lines @@
   });
 
   test('is cleared when search cleared', function() {
     action = select(['1', '2', '3'], '3', false);
     state = bookmarks.SelectionState.updateSelection(state, action);
 
     action = bookmarks.actions.clearSearch();
     state = bookmarks.SelectionState.updateSelection(state, action);
     assertDeepEquals({}, state.items);
   });
+
+  test('deselect items', function() {
+    action = select(['1', '2', '3'], '3', false);
+    state = bookmarks.SelectionState.updateSelection(state, action);
+
+    action = bookmarks.actions.deselectItems();
+    state = bookmarks.SelectionState.updateSelection(state, action);
+    assertDeepEquals({}, state.items);
+  });
 });
 
 suite('closed folder state', function() {
   var nodes;
   var state;
   var action;
 
   setup(function() {
     nodes = testTree(
         createFolder(
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     // Case 2: Clear search by selecting a new folder.
     action = bookmarks.actions.selectFolder('2');
     var selectedState = bookmarks.reduceAction(searchedState, action);
 
     assertEquals('2', selectedState.selectedFolder);
     assertDeepEquals(['3'], bookmarks.util.getDisplayedList(selectedState));
     assertEquals('', selectedState.search.term);
     assertDeepEquals([], selectedState.search.results);
   });
 });