[UI Cocoa] Hide the global error bubble icon from accessibility

ui/base/cocoa/a11y_util.h

+// 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.
+
+#ifndef UI_BASE_COCOA_A11Y_UTIL_H
+#define UI_BASE_COCOA_A11Y_UTIL_H
+
+#import <Cocoa/Cocoa.h>
+
+#include "ui/base/ui_base_export.h"
+
+namespace ui {
+namespace a11y_util {
+
+// Hides the given |view| from the accessibility order for Voice Over. This
+// should be used when the view provides no additional information with
+// voice over (i.e., an icon next to a written description of the icon).
+UI_BASE_EXPORT void HideImageFromAccessibilityOrder(NSImageView* view);
+
+}  // namespace a11y_util
+}  // namespace ui
+
+#endif  // UI_BASE_COCOA_A11Y_UTIL_H