mash: Move ownership of ShelfDelegate to WmShell

ash/test/shell_test_api.cc

Index: ash/test/shell_test_api.cc
diff --git a/ash/test/shell_test_api.cc b/ash/test/shell_test_api.cc
index 457d201f97d5f0fb2dfa3cf7075a32c0b4635eec..b904335223a6c3db14874230cfbd1be2b268a88b 100644
--- a/ash/test/shell_test_api.cc
+++ b/ash/test/shell_test_api.cc
@@ -9,7 +9,6 @@
 #include "ash/common/shell_delegate.h"
 #include "ash/display/display_configuration_controller.h"
 #include "ash/root_window_controller.h"
-#include "ash/shelf/shelf_delegate.h"
 #include "ash/shell.h"
 
 namespace ash {
@@ -50,10 +49,6 @@ void ShellTestApi::DisableDisplayAnimator() {
   shell_->display_configuration_controller()->ResetAnimatorForTest();
 }
 
-void ShellTestApi::SetShelfDelegate(ShelfDelegate* delegate) {
-  shell_->shelf_delegate_.reset(delegate);
-}
-
 void ShellTestApi::SetSessionStateDelegate(
     SessionStateDelegate* session_state_delegate) {
   shell_->session_state_delegate_.reset(session_state_delegate);