Update some spinners on ChromeOS to Material.

ui/file_manager/gallery/css/gallery.css

Index: ui/file_manager/gallery/css/gallery.css
diff --git a/ui/file_manager/gallery/css/gallery.css b/ui/file_manager/gallery/css/gallery.css
index 37aa6fc9cbb519528e2b2e8f1748063d79492ce2..cff180288b96318952a31f6a9974eaf9243b705f 100644
--- a/ui/file_manager/gallery/css/gallery.css
+++ b/ui/file_manager/gallery/css/gallery.css
@@ -1111,15 +1111,15 @@ input[type='checkbox']:checked {
 
 .gallery .spinner {
   background-image:
-      url(../../file_manager/foreground/images/common/spinner.svg);
+      url(chrome://resources/images/throbber.svg);
   background-size: 100%;
-  height: 16px;
+  height: 32px;

[Evan Stade, 2015/05/07 22:53:45]

This change is somewhat tangential to changing the asset, but I noticed the
gallery's spinner looked too small. The video player uses the spinner in a very
similar way and makes it 32x32, so I matched that here.

   left: 50%;
-  margin-left: -8px;
-  margin-top: -8px;
+  margin-left: -16px;
+  margin-top: -16px;
   position: absolute;
   top: 50%;
-  width: 16px;
+  width: 32px;
 }
 
 .gallery:not([spinner]) .spinner {