Implement MD simple gesture nav

ui/resources/vector_icons/vector_icons.cc.template

+// 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.
+
+// vector_icons.cc.template is used to generate vector_icons.cc. Edit the former
+// rather than the latter.
+
+#include "ui/resources/vector_icons/vector_icons.h"
+
+#include "base/logging.h"
+#include "ui/gfx/vector_icon_types.h"
+
+#define PATH_ELEMENT_TEMPLATE(path_name, ...) \
+static constexpr gfx::PathElement path_name[] = {__VA_ARGS__};
+
+#define VECTOR_ICON_TEMPLATE(icon_name, path_name, path_name_1x) \
+const gfx::VectorIcon icon_name = { path_name , path_name_1x };
+
+namespace ui {
+
+using namespace gfx;
+
+TEMPLATE_PLACEHOLDER
+
+}  // namespace ash