Make the app list use images for the progress bar.

ui/resources/ui_resources.grd

Index: ui/resources/ui_resources.grd
diff --git a/ui/resources/ui_resources.grd b/ui/resources/ui_resources.grd
index ccac364d5c6964b0c7bf23a61e7df013ab94b270..d44f283f821ce8389a66b5e371169f1f27bc7807 100644
--- a/ui/resources/ui_resources.grd
+++ b/ui/resources/ui_resources.grd
@@ -20,6 +20,12 @@
       <!-- KEEP THESE IN ALPHABETICAL ORDER!  DO NOT ADD TO RANDOM PLACES JUST
            BECAUSE YOUR RESOURCES ARE FUNCTIONALLY RELATED OR FALL UNDER THE
            SAME CONDITIONALS. -->
+      <if expr="pp_ifdef('enable_app_list')">
+        <structure type="chrome_scaled_image" name="IDR_APP_LIST_ITEM_PROGRESS_BACKGROUND" file="common/app_list_progress_bar_background.png" />
+        <structure type="chrome_scaled_image" name="IDR_APP_LIST_ITEM_PROGRESS_LEFT" file="common/app_list_progress_bar_left.png" />
+        <structure type="chrome_scaled_image" name="IDR_APP_LIST_ITEM_PROGRESS_CENTER" file="common/app_list_progress_bar_center.png" />
+        <structure type="chrome_scaled_image" name="IDR_APP_LIST_ITEM_PROGRESS_RIGHT" file="common/app_list_progress_bar_right.png" />
+      </if>
       <structure type="chrome_scaled_image" name="IDR_APP_TOP_CENTER" file="app_top_center.png" />
       <if expr="pp_ifdef('toolkit_views')">
         <structure type="chrome_scaled_image" name="IDR_APP_TOP_LEFT" file="app_top_left.png" />