Hide AXPlatformNode on ChromeOS.

ui/views/accessibility/native_view_accessibility_stub.cc

Index: ui/views/accessibility/native_view_accessibility_stub.cc
diff --git a/ui/views/accessibility/native_view_accessibility_stub.cc b/ui/views/accessibility/native_view_accessibility_stub.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e40582b10541f98c8d872ba6f8ea43d0070ea221
--- /dev/null
+++ b/ui/views/accessibility/native_view_accessibility_stub.cc
@@ -0,0 +1,15 @@
+// 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.
+
+#include "ui/views/accessibility/native_view_accessibility_base.h"
+
+namespace views {
+
+// static
+std::unique_ptr<NativeViewAccessibilityBase>
+NativeViewAccessibilityBase::Create(View* view) {
+  return nullptr;

[tapted, 2017/03/20 10:36:11]

we could also return a dummy object here, but view.cc has null checks whenever
it accesses |native_view_accessibility_|, so this should be fine.

An alternative is to provide the same "never returns null" guarantee that
AXPlatformNode now has - that might neaten up some of the call sites in view.cc.

(i.e. by implementing a concrete "stub" class that just returns null from
GetNativeObject)

[dmazzoni, 2017/03/20 15:44:06]

Semantically this approach seems more clear than a stub class - it makes more
sense
to say that we don't have or need an implementation on some platforms rather
than
saying we're going to create an instance for every view that does nothing.

+}
+
+}  // namespace views