MacViews/a11y: Implement NativeViewAccessibilityMac.

ui/views/accessibility/native_view_accessibility_mac.h

+// Copyright 2017 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 UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_MAC_H_
+#define UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_MAC_H_
+
+#include "base/macros.h"
+#include "ui/views/accessibility/native_view_accessibility.h"
+
+namespace views {
+
+// Mac-specific accessibility class for NativeViewAccessibility.
+class NativeViewAccessibilityMac : public NativeViewAccessibility {
+ public:
+  explicit NativeViewAccessibilityMac(View* view);
+
+  // NativeViewAccessibility:
+  gfx::NativeViewAccessible GetParent() override;
+
+  DISALLOW_COPY_AND_ASSIGN(NativeViewAccessibilityMac);
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_MAC_H_