Fix scroll regression when specifying an extension id.

chrome/browser/resources/extensions/extension_list.js

Index: chrome/browser/resources/extensions/extension_list.js
diff --git a/chrome/browser/resources/extensions/extension_list.js b/chrome/browser/resources/extensions/extension_list.js
index f6967bd6297656b638d75cb63c44064ba79773fc..041ae9914944c3deded36c2aad1d3f01bd21baa8 100644
--- a/chrome/browser/resources/extensions/extension_list.js
+++ b/chrome/browser/resources/extensions/extension_list.js
@@ -235,6 +235,16 @@ cr.define('extensions', function() {
       /** @private {!Array<ExtensionInfo>} */
       this.extensions_ = [];
 
+      /**
+       * |loadFinished| should be used for testing purposes and will be
+       * fulfilled when this list has finished loading the first time.
+       * @type {Promise}
+       * */
+      this.loadFinished = new Promise(function(resolve, reject) {
+        /** @private {function(?)} */
+        this.onLoadFinish_ = resolve;
+      }.bind(this));
+
       chrome.developerPrivate.onItemStateChanged.addListener(
           function(eventData) {
         var EventType = chrome.developerPrivate.EventType;
@@ -285,11 +295,43 @@ cr.define('extensions', function() {
           this.extensions_ = extensions;
           this.showExtensionNodes_();
           resolve();
+
+          // |resolve| is async so it's necessary to use |then| here in order to
+          // do work after other |then|s have finished.
+          this.extensionsUpdated_.then(function() {

[Dan Beam, 2015/04/18 01:28:40]

why not:

  this.loadFinished_ = this.extensionUpdated_.then(...);

?

[hcarmona, 2015/04/20 17:51:08]

|updateExtensionsData| is called async, so the test wouldn't have a
reference to the |loadFinished_| promise. Also, by assigning
|loadFinished_| in |initialize| the promise will only resolve once.

[Dan Beam, 2015/04/20 17:56:00]

ok, makes sense.  thanks for explanation.

+            // |onUpdateFinished_| should be called after the list becomes
+            // visible in extensions.js.
+            this.onUpdateFinished_();
+
+            // |onLoadFinish_| will resolve the |loadFinished| promise for
+            // testing purposes.
+            this.onLoadFinish_();
+          }.bind(this));
         }.bind(this));
       }.bind(this));
       return this.extensionsUpdated_;
     },
 
+    /** Updates elements that need to be visible in order to update properly. */

[Dan Beam, 2015/04/18 01:28:41]

/**
 * Updates ...
 * @private
 */

[hcarmona, 2015/04/20 17:51:08]

Done.

+    onUpdateFinished_: function() {
+      // Cannot focus or highlight a extension if there are none.
+      if (this.extensions_.length == 0)
+        return;
+
+      assert(!this.hidden);
+      assert(!this.parentElement.hidden);
+
+      this.updateFocusableElements();
+
+      var idToHighlight = this.getIdQueryParam_();
+      if (idToHighlight && $(idToHighlight))
+        this.scrollToNode_(idToHighlight);
+
+      var idToOpenOptions = this.getOptionsQueryParam_();
+      if (idToOpenOptions && $(idToOpenOptions))
+        this.showEmbeddedExtensionOptions_(idToOpenOptions, true);
+    },
+
     /** @return {number} The number of extensions being displayed. */
     getNumExtensions: function() {
       return this.extensions_.length;
@@ -339,14 +381,6 @@ cr.define('extensions', function() {
           assertInstanceof(node, ExtensionFocusRow).destroy();
         }
       }
-
-      var idToHighlight = this.getIdQueryParam_();
-      if (idToHighlight && $(idToHighlight))
-        this.scrollToNode_(idToHighlight);
-
-      var idToOpenOptions = this.getOptionsQueryParam_();
-      if (idToOpenOptions && $(idToOpenOptions))
-        this.showEmbeddedExtensionOptions_(idToOpenOptions, true);
     },
 
     /** Updates each row's focusable elements without rebuilding the grid. */