Add simple mash context menu support.

ash/mus/context_menu_mus.cc

Index: ash/mus/context_menu_mus.cc
diff --git a/ash/mus/context_menu_mus.cc b/ash/mus/context_menu_mus.cc
new file mode 100644
index 0000000000000000000000000000000000000000..50f03a7a42862da67c90678406f658bb1ce88965
--- /dev/null
+++ b/ash/mus/context_menu_mus.cc
@@ -0,0 +1,59 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ash/mus/context_menu_mus.h"
+
+#include "ash/desktop_background/user_wallpaper_delegate.h"
+#include "ash/shelf/shelf.h"
+#include "ash/shelf/shelf_types.h"
+#include "ash/shell.h"
+#include "grit/ash_strings.h"
+
+namespace ash {
+
+ContextMenuMus::ContextMenuMus(ash::Shelf* shelf)
+    : ui::SimpleMenuModel(nullptr), shelf_(shelf), alignment_menu_(shelf) {
+  DCHECK(shelf_);
+  set_delegate(this);
+  AddCheckItemWithStringId(MENU_AUTO_HIDE,
+                           IDS_ASH_SHELF_CONTEXT_MENU_AUTO_HIDE);
+  AddSubMenuWithStringId(MENU_ALIGNMENT_MENU,
+                         IDS_ASH_SHELF_CONTEXT_MENU_POSITION, &alignment_menu_);
+#if defined(OS_CHROMEOS)
+  AddItemWithStringId(MENU_CHANGE_WALLPAPER, IDS_AURA_SET_DESKTOP_WALLPAPER);
+#endif
+}
+
+ContextMenuMus::~ContextMenuMus() {}
+
+bool ContextMenuMus::IsCommandIdChecked(int command_id) const {
+  if (command_id == MENU_AUTO_HIDE)
+    return shelf_->GetAutoHideBehavior() == SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS;
+  return false;
+}
+
+bool ContextMenuMus::IsCommandIdEnabled(int command_id) const {
+  Shell* shell = Shell::GetInstance();
+  if (command_id == MENU_CHANGE_WALLPAPER)
+    return shell->user_wallpaper_delegate()->CanOpenSetWallpaperPage();
+  return true;
+}
+
+bool ContextMenuMus::GetAcceleratorForCommandId(int command_id,
+                                                ui::Accelerator* accelerator) {
+  return false;
+}
+
+void ContextMenuMus::ExecuteCommand(int command_id, int event_flags) {
+  if (command_id == MENU_AUTO_HIDE) {
+    shelf_->SetAutoHideBehavior(shelf_->GetAutoHideBehavior() ==
+                                        SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS
+                                    ? SHELF_AUTO_HIDE_BEHAVIOR_NEVER
+                                    : SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS);
+  } else if (command_id == MENU_CHANGE_WALLPAPER) {
+    Shell::GetInstance()->user_wallpaper_delegate()->OpenSetWallpaperPage();
+  }
+}
+
+}  // namespace ash