Introduce App Launcher for Windows.

ui/app_list/app_list_view_delegate.h

Index: ui/app_list/app_list_view_delegate.h
diff --git a/ui/app_list/app_list_view_delegate.h b/ui/app_list/app_list_view_delegate.h
index d7e0c82f638e881b910223d7609aebba7054700f..f23697153307a60f286d34bee02249debb0cd11f 100644
--- a/ui/app_list/app_list_view_delegate.h
+++ b/ui/app_list/app_list_view_delegate.h
@@ -7,6 +7,10 @@
 
 #include "ui/app_list/app_list_export.h"
 
+namespace gfx {
+class ImageSkia;
+}
+
 namespace app_list {
 
 class AppListItemModel;
@@ -46,6 +50,9 @@ class APP_LIST_EXPORT AppListViewDelegate {
 
   // Invoked to close app list.
   virtual void Close() = 0;
+
+  // Get the application icon to be used, if any, for the app list.
+  virtual gfx::ImageSkia GetWindowAppIcon() = 0;
 };
 
 }  // namespace app_list