[WIP] MD Bookmarks Drag and Drop.

chrome/browser/resources/md_bookmarks/shared_style.html

Index: chrome/browser/resources/md_bookmarks/shared_style.html
diff --git a/chrome/browser/resources/md_bookmarks/shared_style.html b/chrome/browser/resources/md_bookmarks/shared_style.html
index da8836705639381499d5b1f68a415c11a4a92008..5e42bb79ded89181fa51f2f4ee1bfef49ee98a73 100644
--- a/chrome/browser/resources/md_bookmarks/shared_style.html
+++ b/chrome/browser/resources/md_bookmarks/shared_style.html
@@ -32,6 +32,34 @@
         height: 32px;
         margin: 0;
       }
+
+      .drag-above::before,
+      .drag-below::after {
+        background-clip: padding-box;
+        background-color: rgb(66, 133, 244);
+        border: 3px solid rgb(66, 133, 244);
+        border-bottom-color: transparent;
+        border-radius: 0;
+        border-top-color: transparent;
+        box-sizing: border-box;
+        content: '';
+        display: block;
+        height: 8px;
+        left: 0;
+        position: absolute;
+        right: 0;
+        z-index: 10;
+      }
+
+      .drag-above::before {
+        top: 0;
+        transform: translateY(-50%);
+      }
+
+      .drag-below::after {
+        bottom: 0;
+        transform: translateY(50%);
+      }
     </style>
   </template>
 </dom-module>