[MD Extensions] Include the manifest code snippet in load errors

chrome/browser/resources/md_extensions/code_section.html

 <link rel="import" href="chrome://resources/html/cr.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-styles/color.html">
 
 <dom-module id="extensions-code-section">
   <template>
     <style>
       [hidden] {
         display: none !important;
       }
@@ skipping 22 matching lines @@
 
       .highlight {
         background: var(--paper-red-100);
       }
 
       #no-code {
         color: var(--paper-grey-800);
         text-align: center;
       }
     </style>
-    <div id="main" hidden$="[[isMainHidden_(code)]]">
+    <div id="main" hidden$="[[isEmpty(code)]]">
       <div id="line-numbers">
         <span>[[computeLineNumbersContent_(code.*)]]</span>
       </div>
       <div id="source">
         <span>[[code.beforeHighlight]]<!-- No whitespace allowed
        --><span class="highlight" title="[[code.message]]"><!--
          -->[[code.highlight]]<!--
      --></span>[[code.afterHighlight]]</span>
       </div>
     </div>
-    <div id="no-code" hidden$="[[!isMainHidden_(code)]]">[[noCodeError]]</div>
+    <div id="no-code" hidden$="[[!isEmpty(code)]]">[[couldNotDisplayCode]]</div>
   </template>
   <script src="chrome://extensions/code_section.js"></script>
 </dom-module>