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

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

Index: chrome/browser/resources/apps_debugger/js/items_list.js
diff --git a/chrome/browser/resources/apps_debugger/js/items_list.js b/chrome/browser/resources/apps_debugger/js/items_list.js
index 999ef37d273e8faaae35901cfa64867c6500a974..489fa9d792c50ac20fc70d1e72f8c4bd2a491341 100644
--- a/chrome/browser/resources/apps_debugger/js/items_list.js
+++ b/chrome/browser/resources/apps_debugger/js/items_list.js
@@ -280,6 +280,18 @@ cr.define('apps_dev_tool', function() {
       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;