Give up focus if the focused view becomes unfocusable

ui/views/focus/focus_manager.h

Index: ui/views/focus/focus_manager.h
diff --git a/ui/views/focus/focus_manager.h b/ui/views/focus/focus_manager.h
index 7d7c7dc16e02454ede26733b6d93178a823eda67..be812f87bf03ec2405e45c918d83655b53039f62 100644
--- a/ui/views/focus/focus_manager.h
+++ b/ui/views/focus/focus_manager.h
@@ -184,6 +184,10 @@ class VIEWS_EXPORT FocusManager {
   // the native focus (so we still get keyboard events).
   void ClearFocus();
 
+  // Revises the focused view. Tries to advance focus if the focused view has
+  // become unfocusable.
+  void ReviseFocusedView();
+
   // Validates the focused view, clearing it if the window it belongs too is not
   // attached to the window hierarchy anymore.
   void ValidateFocusedView();