Replace deprecated iron-flex-layout/classes with iron-flex-layout-class in MD Settings

chrome/browser/resources/settings/appearance_page/appearance_page.html

Index: chrome/browser/resources/settings/appearance_page/appearance_page.html
diff --git a/chrome/browser/resources/settings/appearance_page/appearance_page.html b/chrome/browser/resources/settings/appearance_page/appearance_page.html
index 8303b98301ad312cf7371bea840d9f9aab3bf17c..87f6571d892e8176e0029e58d9477606ff1b37aa 100644
--- a/chrome/browser/resources/settings/appearance_page/appearance_page.html
+++ b/chrome/browser/resources/settings/appearance_page/appearance_page.html
@@ -1,6 +1,5 @@
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
-<link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/classes/iron-flex-layout.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/neon-animation/neon-animatable.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
@@ -43,13 +42,10 @@
         <div class="settings-box two-line first"
             hidden="[[!pageVisibility.setTheme]]">
 </if>
-          <div class="layout horizontal center flex"
-              on-tap="openThemesGallery_" actionable>
-            <iron-icon icon="settings:palette"></iron-icon>
-            <div>
-              <div>$i18n{getThemes}</div>
-              <div class="secondary">[[themeSublabel_]]</div>
-            </div>
+          <iron-icon icon="settings:palette"></iron-icon>
+          <div class="start" on-tap="openThemesGallery_" actionable>
+            <div>$i18n{getThemes}</div>
+            <div class="secondary">[[themeSublabel_]]</div>
           </div>
           <template is="dom-if" if="[[allowResetTheme_]]">
             <div class="secondary-action">