[MD Bookmarks] Remove the bookmarks-sidebar element.

chrome/browser/resources/md_bookmarks/folder_node.html

Index: chrome/browser/resources/md_bookmarks/folder_node.html
diff --git a/chrome/browser/resources/md_bookmarks/folder_node.html b/chrome/browser/resources/md_bookmarks/folder_node.html
index 6b6ac2622029cf036cce13cd72d7d34bbca7a850..7f38457b8be7b3229f8b8fa479c91ee6a7281a66 100644
--- a/chrome/browser/resources/md_bookmarks/folder_node.html
+++ b/chrome/browser/resources/md_bookmarks/folder_node.html
@@ -81,7 +81,8 @@
     </style>
 
     <div id="container" class="v-centered" on-tap="selectFolder_"
-        draggable="[[!isRootFolder_(depth)]]">
+        draggable="[[!isRootFolder_(depth)]]"

[tsergeant, 2017/04/19 07:39:28]

Nit: Maybe we should name these a bit more consistently with the rest of the app
(which refers to the root folder as something else)

isRootFolder could become isTopLevelFolder
and !isPositiveDepth_ could become isRootFolder (ie, depth == -1)

[calamity, 2017/04/26 08:03:54]

Donion rings.

+        hidden="[[!isPositiveDepth_(depth)]]">
       <template is="dom-if" if="[[hasChildFolder_(item_.children)]]">
         <paper-icon-button id="arrow" icon="cr:arrow-drop-down"
             is-open$="[[!isClosed_]]" on-tap="toggleFolder_">