MD Extensions: Show messages for no extensions, and for no search results

chrome/browser/resources/md_extensions/manager.js

Index: chrome/browser/resources/md_extensions/manager.js
diff --git a/chrome/browser/resources/md_extensions/manager.js b/chrome/browser/resources/md_extensions/manager.js
index f4070d37b73b4b8164fb36dfed76b601e67e19fe..a8a59ed8114b5fcd142f3247bed2576d786e7fe5 100644
--- a/chrome/browser/resources/md_extensions/manager.js
+++ b/chrome/browser/resources/md_extensions/manager.js
@@ -98,6 +98,15 @@ cr.define('extensions', function() {
           return [];
         },
       },
+
+      /**
+       * Prevents page content from showing before data is first loaded.
+       * @private
+       */
+      didInitPage_: {
+        type: Boolean,
+        value: false,
+      },
     },
 
     listeners: {
@@ -171,6 +180,7 @@ cr.define('extensions', function() {
      * the user visits chrome://extensions/?id=..., we land on the proper page.
      */
     initPage: function() {
+      this.didInitPage_ = true;
       this.changePage(this.navigationHelper_.getCurrentPage(), true);
     },
 
@@ -236,14 +246,6 @@ cr.define('extensions', function() {
     },
 
     /**
-     * @return {boolean} Whether the list should be visible.
-     * @private
-     */
-    computeListHidden_: function() {
-      return this.$['items-list'].items.length == 0;
-    },
-
-    /**
      * Creates and adds a new extensions-item element to the list, inserting it
      * into its sorted position in the relevant section.
      * @param {!chrome.developerPrivate.ExtensionInfo} item The extension