[MD Bookmarks] Add UI for multi-item drag and drop chip.

chrome/browser/resources/md_bookmarks/dnd_chip.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://bookmarks/shared_style.html">
 
 <dom-module id="bookmarks-dnd-chip">
   <template>
     <style include="shared-style">
       :host {
-        align-items: center;
-        background-color: var(--interactive-color);
-        border-radius: 20px;
-        box-shadow: 0 0 8px 0 rgba(0,0,0,0.12), 0 8px 8px 0 rgba(0,0,0,0.24);
-        display: none;
-        height: 40px;
+        --chip-height: 40px;
+        --chip-padding-x: 20px;
+        --chip-width: 172px;
+
         left: 0;
-        padding: 0 20px;
         pointer-events: none;
         position: absolute;
         top: 0;
-        transform: translate(
-            calc(var(--mouse-x) - 50%), calc(var(--mouse-y) - 80%));
-        width: 132px;
+        transform: translate(calc(var(--mouse-x) - var(--chip-width) * 0.5),
+                             calc(var(--mouse-y) - var(--chip-height) * 0.8));
+        z-index: 2;
       }
 
-      :host([showing_]) {
-        display: flex;
+      :host(:not([showing_])) {
+        display: none;
+      }
+
+      .chip-container {
+        background-color: var(--interactive-color);
+        border-radius: calc(var(--chip-height) / 2);
+        box-shadow: 0 0 8px 0 rgba(0, 0, 0, 0.12),
+                    0 8px 8px 0 rgba(0, 0, 0, 0.24);
+        height: var(--chip-height);
+        left: 0;
+        padding: 0 var(--chip-padding-x);
+        position: absolute;
+        top: 0;
+        width: calc(var(--chip-width) - var(--chip-padding-x) * 2);
+      }
+
+      #secondary {
+        left: 5px;
+        top: 5px;
       }
 
       #title {
         -webkit-margin-start: 20px;
         color: white;
         flex: 1;
         font-weight: 500;
         overflow: hidden;
         text-decoration: none;
         text-overflow: ellipsis;
         white-space: nowrap;
       }
 
       #icon-wrapper {
-        align-items: center;
         background: white;
         border-radius: 12px;
         color: var(--secondary-text-color);
-        display: flex;
         height: 24px;
-        justify-content: center;
         position: relative;
         width: 24px;
       }
 
       #icon {
         background-repeat: no-repeat;
         height: 16px;
         margin: 2px;
         width: 16px;
       }
+
+      .centered {
+        align-items: center;
+        display: flex;
+        justify-content: center;
+      }
+
+      #count {
+        background: var(--google-red-500);
+        border-radius: 12px;
+        color: white;
+        font-weight: 500;
+        height: 24px;
+        min-width: 14px;
+        padding: 0 5px;
+        position: absolute;
+        right: -170px;
+        top: -10px;
+      }
+
+      :host-context([dir='rtl']) #count {
+        left: 2px;
+        right: auto;
+      }
     </style>
-    <div id="icon-wrapper">
-      <iron-icon id="folder-icon" icon="cr:folder" hidden$="[[!isFolder_]]">
-      </iron-icon>
-      <div id="icon" hidden$="[[isFolder_]]"></div>
+    <div id="secondary" class="chip-container" hidden$="[[!isMultiItem_]]">
     </div>
-    <div id="title"></div>
+    <div id="primary" class="chip-container centered">
+      <div id="icon-wrapper" class="centered">
+        <iron-icon id="folder-icon" icon="cr:folder" hidden$="[[!isFolder_]]">
+        </iron-icon>
+        <div id="icon" hidden$="[[isFolder_]]"></div>
+      </div>
+      <div id="title"></div>
+    </div>
+    <div id="count" class="centered" hidden$="[[!isMultiItem_]]"></div>
   </template>
   <script src="chrome://bookmarks/dnd_chip.js"></script>
 <dom-module>