Resurrect Aura Linux accessibility.

ui/accessibility/platform/ax_platform_node.cc

 // Copyright 2014 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.
 
 #include "ui/accessibility/platform/ax_platform_node.h"
 
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/accessibility/platform/ax_platform_node_delegate.h"
 
 namespace ui {
 
-#if !defined(OS_MACOSX) && !defined(OS_WIN)
+#if !defined(OS_MACOSX) && !defined(OS_WIN) && !(defined(OS_LINUX) && !defined(OS_CHROMEOS))
 // static
 AXPlatformNode* AXPlatformNode::Create(AXPlatformNodeDelegate* delegate) {
   return nullptr;
 }
 #endif
 
 #if !defined(OS_WIN)
 // This is the default implementation for platforms where native views
 // accessibility is unsupported or unfinished.
 //
 // static
 AXPlatformNode* AXPlatformNode::FromNativeViewAccessible(
     gfx::NativeViewAccessible accessible) {
   return nullptr;
 }
 #endif
 
 AXPlatformNode::AXPlatformNode() {
 }
 
 AXPlatformNode::~AXPlatformNode() {
 }
 
 }  // namespace ui