[MD Bookmarks] Make dragging update selected items.

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

Index: chrome/test/data/webui/md_bookmarks/dnd_manager_test.js
diff --git a/chrome/test/data/webui/md_bookmarks/dnd_manager_test.js b/chrome/test/data/webui/md_bookmarks/dnd_manager_test.js
index 2c373334b7acca39884fb677ab14ec2bdd1e1ac3..d0276a1d2dcb5341f542b73331aa23e24118d426 100644
--- a/chrome/test/data/webui/md_bookmarks/dnd_manager_test.js
+++ b/chrome/test/data/webui/md_bookmarks/dnd_manager_test.js
@@ -471,4 +471,24 @@ suite('drag and drop', function() {
         DropPosition.NONE, dndManager.calculateValidDropPositions_(dragTarget));
     assertDragStyle(dragTarget, DRAG_STYLE.NONE);
   });
+
+  test('drag item selects/deselects items', function() {
+    store.setReducersEnabled(true);
+
+    store.data.selection.items = new Set(['13', '15']);
+    store.notifyObservers();
+
+    // Dragging an item not in the selection selects the dragged item and
+    // deselects the previous selection.
+    var dragElement = getListItem('14');
+    dispatchDragEvent('dragstart', dragElement);
+    assertDeepEquals(['14'], normalizeSet(store.data.selection.items));
+    dispatchDragEvent('dragend', dragElement);
+
+    // Dragging a folder node deselects any selected items in the bookmark list.
+    dragElement = getFolderNode('15');
+    dispatchDragEvent('dragstart', dragElement);
+    assertDeepEquals([], normalizeSet(store.data.selection.items));
+    dispatchDragEvent('dragend', dragElement);
+  });
 });