[MD Bookmarks] Add skeleton for MD Bookmarks.

chrome/browser/resources/md_bookmarks/toolbar.html

+<link rel="import" href="chrome://resources/html/polymer.html">
+<link rel="import" href="chrome://resources/cr_elements/cr_action_menu/cr_action_menu.html">
+<link rel="import" href="chrome://resources/cr_elements/cr_toolbar/cr_toolbar.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
+<link rel="import" href="chrome://bookmarks/shared_style.html">
+<link rel="stylesheet" href="chrome://resources/css/md_colors.css">
+
+<dom-module id="bookmarks-toolbar">
+  <template>
+    <style include="shared-style">
+      button.more-actions {
+        margin: 4px;
+      }
+
+      button.more-vert-button div {
+        border-color: white;
+      }
+
+      cr-toolbar {
+        --cr-toolbar-field-margin: var(--sidebar-width);
+        background: var(--md-toolbar-color);
+      }
+    </style>
+    <dialog is="cr-action-menu" id="dropdown">
+      <button class="dropdown-item" on-tap="onBulkEditTap_">
+        $i18n{menuBulkEdit}
+      </button>
+      <button class="dropdown-item" on-tap="onSortTap_">
+        $i18n{menuSort}
+      </button>
+      <hr>
+      <button class="dropdown-item" on-tap="onAddBookmarkTap_">
+        $i18n{menuAddBookmark}
+      </button>
+      <button class="dropdown-item" on-tap="onAddFolderTap_">
+        $i18n{menuAddFolder}
+      </button>
+      <hr>
+      <button class="dropdown-item" on-tap="onImportTap_">
+        $i18n{menuImport}
+      </button>
+      <button class="dropdown-item" on-tap="onExportTap_">
+        $i18n{menuExport}
+      </button>
+    </dialog>
+    <cr-toolbar page-name="$i18n{title}"
+        clear-label="$i18n{clearSearch}"
+        search-prompt="$i18n{searchPrompt}">
+      <button is="paper-icon-button-light" class="more-actions more-vert-button"
+          on-tap="onMenuButtonOpenTap_">
+        <div></div>
+        <div></div>
+        <div></div>
+      </button>
+    </cr-toolbar>
+  </template>
+  <script src="chrome://bookmarks/toolbar.js"></script>
+</dom-module>