Re-land: Resurrect Aura Linux accessibility.

ui/accessibility/platform/ax_platform_node_auralinux.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 UI_ACCESSIBILITY_AX_PLATFORM_NODE_AURALINUX_H_
+#define UI_ACCESSIBILITY_AX_PLATFORM_NODE_AURALINUX_H_
+
+#include <atk/atk.h>
+
+#include "ui/accessibility/ax_export.h"
+#include "ui/accessibility/platform/ax_platform_node_base.h"
+
+namespace ui {
+
+// Implements accessibility on Aura Linux using ATK.
+class AXPlatformNodeAuraLinux : public AXPlatformNodeBase {
+ public:
+  AXPlatformNodeAuraLinux();
+
+  // Set or get the root-level Application object that's the parent of all
+  // top-level windows.
+  AX_EXPORT static void SetApplication(AXPlatformNode* application);
+  static AXPlatformNode* application() { return application_; }
+
+  AtkRole GetAtkRole();
+
+  // AXPlatformNode overrides.
+  void Destroy() override;
+  gfx::NativeViewAccessible GetNativeViewAccessible() override;
+  void NotifyAccessibilityEvent(ui::AXEvent event_type) override;
+
+  // AXPlatformNodeBase overrides.
+  void Init(AXPlatformNodeDelegate* delegate) override;
+  int GetIndexInParent() override;
+
+ private:
+  ~AXPlatformNodeAuraLinux() override;
+
+  // We own a reference to this ref-counted object.
+  AtkObject* atk_object_;
+
+  // The root-level Application object that's the parent of all
+  // top-level windows.
+  static AXPlatformNode* application_;
+
+  DISALLOW_COPY_AND_ASSIGN(AXPlatformNodeAuraLinux);
+};
+
+}  // namespace ui
+
+#endif  // UI_ACCESSIBILITY_AX_PLATFORM_NODE_AURALINUX_H_