Add kAccessibilityFocusFallsbackToWidget property

components/exo/shell_surface.cc

Index: components/exo/shell_surface.cc
diff --git a/components/exo/shell_surface.cc b/components/exo/shell_surface.cc
index d8b5e7bf93935ef26dd9c7197b5e23f402382458..cd7e94ccfc4c59f356366976a98badb856a38d71 100644
--- a/components/exo/shell_surface.cc
+++ b/components/exo/shell_surface.cc
@@ -1020,6 +1020,11 @@ void ShellSurface::CreateShellSurfaceWidget(ui::WindowShowState show_state) {
   widget_ = new ShellSurfaceWidget(this);
   widget_->Init(params);
 
+  views::View* root_view = widget_->GetRootView();
+  if (root_view != nullptr) {

[reveman, 2016/11/30 17:00:40]

nit: s/root_view != nullptr/root_view/

when is this null? DCHECK instead?

[yawano, 2016/12/01 00:24:23]

Done. I don't come up case where it becomes null. DCHECK will be enough.

+    root_view->SetFocusBehavior(views::View::FocusBehavior::NEVER);

[reveman, 2016/11/30 17:00:40]

Can you explain in the description of this change why we want this for all exo
shell surfaces? I'm failing to see what any of this has to do with BubbleWidgets
as mentioned in the description..

[yawano, 2016/12/01 00:24:23]

Added comment.

+  }
+
   aura::Window* window = widget_->GetNativeWindow();
   window->SetName("ExoShellSurface");
   window->AddChild(surface_->window());