Moves home card background to HomeCardView.

athena/home/athena_start_page_view.h

Index: athena/home/athena_start_page_view.h
diff --git a/athena/home/athena_start_page_view.h b/athena/home/athena_start_page_view.h
index a98e9c2bb2a865ad11915fc057524b67491d293e..fd15dca207585e2aaf899c7ca1caffe8bc219ba2 100644
--- a/athena/home/athena_start_page_view.h
+++ b/athena/home/athena_start_page_view.h
@@ -63,7 +63,6 @@ class ATHENA_EXPORT AthenaStartPageView
     gfx::Rect controls;
     float system_info_opacity;
     float logo_opacity;
-    float background_opacity;
 
     LayoutData();
   };
@@ -110,10 +109,6 @@ class ATHENA_EXPORT AthenaStartPageView
   app_list::SearchBoxView* search_box_view_;
   app_list::SearchResultListView* search_results_view_;
 
-  // Do not use views::Background but a views::View with ui::Layer for gradient
-  // background opacity update and animation.
-  views::View* background_;
-
   // The expected height of |search_results_view_|
   int search_results_height_;