MD Bookmarks: Support policies for disabling bookmark editing

chrome/browser/resources/md_bookmarks/dnd_manager.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.
 
 cr.define('bookmarks', function() {
   /**
    * @param {BookmarkElement} element
    * @return {boolean}
    */
   function isBookmarkItem(element) {
@@ skipping 408 matching lines @@
             clear: false,
             range: false,
             toggle: false,
           }));
         }
         draggedNodes = [dragId];
       }
 
       e.preventDefault();
 
+      // If any node can't be dragged, early return (after preventDefault).
+      var anyUnmodifiable = draggedNodes.some(function(itemId) {
+        return !bookmarks.util.canEditNode(state, itemId);
+      });
+      if (anyUnmodifiable)
+        return;
+
       // If we are dragging a single link, we can do the *Link* effect.
       // Otherwise, we only allow copy and move.
       if (e.dataTransfer) {
         e.dataTransfer.effectAllowed =
             draggedNodes.length == 1 && state.nodes[draggedNodes[0]].url ?
             'copyLink' :
             'copyMove';
       }
 
       // TODO(calamity): account for touch.
@@ skipping 29 matching lines @@
       e.preventDefault();
 
       if (!this.dragInfo_.isDragValid())
         return;
 
       var overElement = getBookmarkElement(e.path);
       this.autoExpander_.update(e, overElement);
       if (!overElement)
         return;
 
-
       // Now we know that we can drop. Determine if we will drop above, on or
       // below based on mouse position etc.
       this.dropDestination_ =
           this.calculateDropDestination_(e.clientY, overElement);
       if (!this.dropDestination_) {
         this.dropIndicator_.finish();
         return;
       }
 
       if (e.dataTransfer) {
@@ skipping 51 matching lines @@
 
       // Drags aren't allowed onto the search result list.
       if ((isBookmarkList(overElement) || isBookmarkItem(overElement)) &&
           bookmarks.util.isShowingSearch(state)) {
         return DropPosition.NONE;
       }
 
       if (isBookmarkList(overElement))
         itemId = state.selectedFolder;
 
+      if (!bookmarks.util.canReorderChildren(state, itemId))
+        return DropPosition.NONE;
+
       // Drags of a bookmark onto itself or of a folder into its children aren't
       // allowed.
       if (dragInfo.isDraggingBookmark(itemId) ||
           dragInfo.isDraggingFolderToDescendant(itemId, state.nodes)) {
         return DropPosition.NONE;
       }
 
       var validDropPositions = this.calculateDropAboveBelow_(overElement);
       if (this.canDropOn_(overElement))
         validDropPositions |= DropPosition.ON;
@@ skipping 76 matching lines @@
       this.dropIndicator_.setTimeout = this.setTimeout_;
     }
   };
 
   return {
     DNDManager: DNDManager,
     DragInfo: DragInfo,
     DropIndicator: DropIndicator,
   };
 });