[Apps Developer Tool] Show installation warnings as chrome://extensions.

chrome/browser/resources/apps_debugger/js/items_list.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 cr.define('apps_dev_tool', function() {
   'use strict';
 
   // The list of all packed/unpacked apps and extensions.
   var completeList = [];
 
@@ skipping 262 matching lines @@
         loadPath.hidden = false;
         loadPath.querySelector('span:nth-of-type(2)').textContent =
             ' ' + item.path;
         this.setPackButton_(item, node);
       }
 
       // Then the 'managed, cannot uninstall/disable' message.
       if (!item.may_disable)
         node.querySelector('.managed-message').hidden = false;
 
+      // The install warnings.
+      if (item.install_warnings.length > 0) {
+        var panel = node.querySelector('.install-warnings');
+        panel.hidden = false;
+        var list = panel.querySelector('ul');
+        item.install_warnings.forEach(function(warning) {
+          var li = document.createElement('li');
+          li[warning.isHTML ? 'innerHTML' : 'textContent'] = warning.message;
+          list.appendChild(li);
+        });
+      }
+
       this.setActiveViews_(item, node);
 
       return node;
     },
 
     /**
      * Sets the webstore link.
      * @param {!Object} item A dictionary of item metadata.
      * @param {!HTMLElement} el HTML element containing all items.
      * @private
@@ skipping 292 matching lines @@
       // node.
       container.scrollTop = node.offsetTop + node.offsetHeight -
           container.offsetHeight + 20;
     }
   };
 
   return {
     ItemsList: ItemsList,
   };
 });