Hide AXPlatformNode on ChromeOS.

ui/base/ui_features.gni

Index: ui/base/ui_features.gni
diff --git a/ui/base/ui_features.gni b/ui/base/ui_features.gni
index b563b2b2b13ae678cc8e08625ba7f7a549f7cf08..bf5bddc1edcacbe67bcbdca6acbd72c301a1b6fb 100644
--- a/ui/base/ui_features.gni
+++ b/ui/base/ui_features.gni
@@ -2,12 +2,17 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/ui.gni")
+
 declare_args() {
   # Optional system library.
   use_xkbcommon = false
 
   # Whether the entire browser uses toolkit-views on Mac instead of Cocoa.
   mac_views_browser = false
+
+  # Whether the platform provides a native accessibility toolkit.
+  has_platform_accessibility = use_atk || is_win || is_mac

[sky, 2017/03/22 15:13:25]

optional: consider naming this has_native_accessibility to better match with
other terms we use, such as nativewidget. Using 'native' also better matches the
file names too, eg native_view_accessibility*

[tapted, 2017/03/22 23:29:20]

Done.

 }
 
 enable_hidpi = is_mac || is_win || is_linux