ash: Move AppList support to ShelfWidget, expose ShelfWidget in WmShelf

ash/common/shelf/shelf.cc

Index: ash/common/shelf/shelf.cc
diff --git a/ash/common/shelf/shelf.cc b/ash/common/shelf/shelf.cc
index ca8fba3bb858dafcfce5ddf213133055f3dc6545..d67925249669b99b2fe52f7b89948646e10df890 100644
--- a/ash/common/shelf/shelf.cc
+++ b/ash/common/shelf/shelf.cc
@@ -5,7 +5,6 @@
 #include "ash/common/shelf/shelf.h"
 
 #include "ash/common/shelf/shelf_delegate.h"
-#include "ash/common/shelf/shelf_view.h"
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/wm_root_window_controller.h"
 #include "ash/common/wm_shell.h"
@@ -38,12 +37,4 @@ Shelf* Shelf::ForWindow(WmWindow* window) {
   return window->GetRootWindowController()->GetShelf()->shelf();
 }
 
-AppListButton* Shelf::GetAppListButton() const {
-  return shelf_view_->GetAppListButton();
-}
-
-app_list::ApplicationDragAndDropHost* Shelf::GetDragAndDropHostForAppList() {
-  return shelf_view_;
-}
-
 }  // namespace ash