mash: Remove ShelfDelegate; move functions to ShelfModel.

ash/shell/shell_delegate_impl.cc

Index: ash/shell/shell_delegate_impl.cc
diff --git a/ash/shell/shell_delegate_impl.cc b/ash/shell/shell_delegate_impl.cc
index 0baaab39c65d3d941cb4a1da978ffe5e2a6f44d5..07dbab73e9e8173ebc619b8c7c684231c545a2b5 100644
--- a/ash/shell/shell_delegate_impl.cc
+++ b/ash/shell/shell_delegate_impl.cc
@@ -17,7 +17,6 @@
 #include "ash/shell/toplevel_window.h"
 #include "ash/system/tray/default_system_tray_delegate.h"
 #include "ash/test/test_keyboard_ui.h"
-#include "ash/test/test_shelf_delegate.h"
 #include "ash/wm/window_state.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
@@ -122,10 +121,6 @@ keyboard::KeyboardUI* ShellDelegateImpl::CreateKeyboardUI() {
 
 void ShellDelegateImpl::OpenUrlFromArc(const GURL& url) {}
 
-ShelfDelegate* ShellDelegateImpl::CreateShelfDelegate(ShelfModel* model) {
-  return new test::TestShelfDelegate();
-}
-
 SystemTrayDelegate* ShellDelegateImpl::CreateSystemTrayDelegate() {
   return new DefaultSystemTrayDelegate;
 }