Reland: Implement Aura side of unified touch text selection for contents

content/browser/renderer_host/input/ui_touch_selection_helper.h

+// Copyright 2015 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.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_UI_TOUCH_SELECTION_HELPER_H_
+#define CONTENT_BROWSER_RENDERER_HOST_UI_TOUCH_SELECTION_HELPER_H_
+
+#include "ui/base/touch/selection_bound.h"
+
+namespace cc {
+struct ViewportSelectionBound;
+}
+
+namespace content {
+
+ui::SelectionBound ConvertSelectionBound(
+    const cc::ViewportSelectionBound& bound);
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_UI_TOUCH_SELECTION_HELPER_H_