Fix custom wallpaper going back from wallpaper 2 to wallpaper 1

chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_images_grid.js

Index: chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_images_grid.js
diff --git a/chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_images_grid.js b/chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_images_grid.js
index 35a0d99103cf1f581303f646577c46265264ef19..e71a44a600eac9b8580942d299e532c9c9e55d6b 100644
--- a/chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_images_grid.js
+++ b/chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_images_grid.js
@@ -247,6 +247,22 @@ cr.define('wallpapers', function() {
     },
 
     /**
+     * Inserts newElement at the position specified by index.
+     * @param {number} index The index of the newElement to insert.
+     * @type {!Object} Wallpaper information inserted into the data model.

[flackr, 2013/04/15 15:02:02]

@param {!Object} newElement
Although I'd prefer this to be called wallpaperInfo instead of newElement since
the list being inserted into contains wallpaper information.

[bshe, 2013/04/15 15:22:10]

Done.

+     */
+    insertElement: function(index, newElement) {
+      // splice may dispatch a change event because the position of selected
+      // element changing. But the actual selected element didn't change after
+      // splice. Sets inProgramSelection to true to disable the event handler of
+      // change event. Otherwise, wallpaper may reset to previous one as

[flackr, 2013/04/15 15:02:02]

Can we not we prevent handling a change event which doesn't change the actual
selected element?

[bshe, 2013/04/15 15:22:10]

Sorry, just to confirm. Do you mean we check if the selected element is the same
as previous one in the event handler? And prevent handling if it is the same as
previous one?

On 2013/04/15 15:02:02, flackr wrote:

[flackr, 2013/04/15 20:00:54]

Yes.

On 2013/04/15 15:22:10, bshe wrote:

[bshe, 2013/04/15 23:38:22]

Done.

+      // described in http://crbug.com/229036.
+      this.inProgramSelection_ = true;
+      this.dataModel.splice(index, 0, newElement);
+      this.inProgramSelection_ = false;
+    },
+
+    /**
      * Forces re-display, size re-calculation and focuses grid.
      */
     updateAndFocus: function() {