MD Settings: Add "Auto Open" setting to Downloads page UI.

chrome/browser/resources/settings/downloads_page/downloads_page.html

Index: chrome/browser/resources/settings/downloads_page/downloads_page.html
diff --git a/chrome/browser/resources/settings/downloads_page/downloads_page.html b/chrome/browser/resources/settings/downloads_page/downloads_page.html
index 64af1e7a93b9f7e9c60d505dc199c1b2a5b38be8..a64812684db8fb406c22813ef6f6fc55bca72c3f 100644
--- a/chrome/browser/resources/settings/downloads_page/downloads_page.html
+++ b/chrome/browser/resources/settings/downloads_page/downloads_page.html
@@ -1,8 +1,10 @@
 <link rel="import" href="chrome://resources/html/polymer.html">
+<link rel="import" href="chrome://resources/html/web_ui_listener_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/classes/iron-flex-layout.html">
 <link rel="import" href="../controls/controlled_button.html">
 <link rel="import" href="../controls/settings_toggle_button.html">
 <link rel="import" href="../settings_shared_css.html">
+<link rel="import" href="downloads_browser_proxy.html">
 
 <dom-module id="settings-downloads-page">
   <template>
@@ -41,6 +43,19 @@
       </settings-toggle-button>
 </if>
     </div>
+    <template is="dom-if" if="[[autoOpenDownloads_]]" restamp>
+      <div class="settings-box">
+        <div class="start">
+          $i18n{openFileTypesAutomatically}
+        </div>
+        <div class="secondary-action">
+          <paper-button id="resetAutoOpenFileTypes" class="secondary-button"
+              on-tap="onClearAutoOpenFileTypesTap_">
+            $i18n{clear}
+          </paper-button>
+        </div>
+      </div>
+    </template>
   </template>
   <script src="downloads_page.js"></script>
 </dom-module>