Hide/show widget on Windows screen lock/unlock

ui/views/view.h

Index: ui/views/view.h
diff --git a/ui/views/view.h b/ui/views/view.h
index 86bed2a0de6f0ba2b990ef53340adcaeb227e48b..195fe51aa8958dcc63147295651f7ad25b62e536 100644
--- a/ui/views/view.h
+++ b/ui/views/view.h
@@ -1082,6 +1082,8 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // FocusManager manages this view.
   virtual void NativeViewHierarchyChanged();
 
+  virtual void OnSoftVisibilityChanged(bool visible) {}
+
   // Painting ------------------------------------------------------------------
 
   // Responsible for calling Paint() on child Views. Override to control the
@@ -1289,6 +1291,8 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // VisibilityChanged().
   void VisibilityChangedImpl(View* starting_from, bool is_visible);
 
+  void PropagateSoftVisibilityChanged(bool visible);
+
   // Responsible for propagating bounds change notifications to relevant
   // views.
   void BoundsChanged(const gfx::Rect& previous_bounds);