MD Bookmarks: Simplify and improve consistency of CSS

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 3166667c0ae2f796455e29840c3ff5c961a339c3..c9bb16c4ecec230448e520615518a6b11159334f 100644
--- a/chrome/browser/resources/md_bookmarks/folder_node.html
+++ b/chrome/browser/resources/md_bookmarks/folder_node.html
@@ -1,8 +1,7 @@
 <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/polymer/v1_0/iron-icon/iron-icon.html">
-<link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
-<link rel="import" href="chrome://resources/polymer/v1_0/paper-styles/color.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="chrome://bookmarks/actions.html">
 <link rel="import" href="chrome://bookmarks/icons.html">
 <link rel="import" href="chrome://bookmarks/shared_style.html">
@@ -52,19 +51,14 @@
       }
 
       iron-icon {
-        --iron-icon-height: 20px;
-        --iron-icon-width: 20px;
-        min-width: 20px;
+        flex-shrink: 0;
       }
 
       #arrow {
         color: var(--secondary-text-color);
-        height: 36px;
         margin: 0 8px;
-        min-width: 36px;
         transform: rotate(-90deg);
         transition: transform 150ms;
-        width: 36px;
       }
 
       :host-context([dir='rtl']) #arrow {
@@ -84,9 +78,10 @@
         draggable="[[!isTopLevelFolder_(depth)]]"
         hidden="[[isRootFolder_(depth)]]">
       <template is="dom-if" if="[[hasChildFolder_(item_.children)]]">
-        <paper-icon-button id="arrow" icon="cr:arrow-drop-down"
+        <button is="paper-icon-button-light" id="arrow"
             is-open$="[[!isClosed_]]" on-tap="toggleFolder_">
-        </paper-icon-button>
+          <iron-icon icon="cr:arrow-drop-down"></iron-icon>
+        </button>
       </template>
       <div id="folder-label" class="v-centered">
         <iron-icon icon="[[getFolderIcon_(isSelectedFolder_)]]"