Fix img misalign and hide "by" when nothing selected in new wallpaepr picker ui

chrome/browser/resources/chromeos/wallpaper_manager/css/wallpaper_manager.css

Index: chrome/browser/resources/chromeos/wallpaper_manager/css/wallpaper_manager.css
diff --git a/chrome/browser/resources/chromeos/wallpaper_manager/css/wallpaper_manager.css b/chrome/browser/resources/chromeos/wallpaper_manager/css/wallpaper_manager.css
index 158cf8ef6377b1480883dc3456a817d4f364669c..67fa60a14ed83321fbac3e9415d12e5a430d2ab6 100644
--- a/chrome/browser/resources/chromeos/wallpaper_manager/css/wallpaper_manager.css
+++ b/chrome/browser/resources/chromeos/wallpaper_manager/css/wallpaper_manager.css
@@ -121,16 +121,30 @@ div.sidebar-splitter {
   width: 128px;
 }
 
+/* The width and height of img tag need to be set here. Otherwise, incorrect
+ * image size may be used when layout. Some images may be misaligned as a
+ * result. See http://code.google.com/p/chromium/issues/detail?id=148480 for
+ * screen shot.

[flackr, 2012/09/13 02:34:27]

This could potentially show images at the wrong aspect ratio, I assume this is
acceptable for the wallpapers we plan to show for now?

[bshe, 2012/09/13 03:45:48]

Yes. All the thumbnails are downloaded from server and their size are 128x80 for
now.

On 2012/09/13 02:34:27, flackr wrote:

+ */
+.image-picker img {
+  height: 80px;
+  width: 128px;
+}
+
 .image-picker [selected][lead] {
   border: 2px solid rgb(0, 102, 204);
   padding: 1px;
 }
 
-.wallpaper-attr {
+#wallpaper-attr {

[flackr, 2012/09/13 02:34:27]

I don't think there's any need to abbreviate this, can we change it to
wallpaper-attribution, which I assume it's short for.

[bshe, 2012/09/13 03:45:48]

Done.

   -webkit-box-orient: vertical;
   display: -webkit-box;
 }
 
+#wallpaper-attr[hidden] {

[flackr, 2012/09/13 02:34:27]

perhaps just *[hidden]?

[bshe, 2012/09/13 03:45:48]

Done.

+  display: none;
+}
+
 .bottom-bar {
   -webkit-box-align: center;
   -webkit-box-orient: horizontal;