Allow updating arc widget bounds in maximize/fullscreen state.

components/exo/shell_surface.h

Index: components/exo/shell_surface.h
diff --git a/components/exo/shell_surface.h b/components/exo/shell_surface.h
index 1f8ee3935225d64ba07daecfc50b2f4e567df0b6..262ce48f9b78ae9a37b798aab82a11061fa1d590 100644
--- a/components/exo/shell_surface.h
+++ b/components/exo/shell_surface.h
@@ -261,6 +261,8 @@ class ShellSurface : public SurfaceDelegate,
   // Updates the bounds of widget to match the current surface bounds.
   void UpdateWidgetBounds();
 
+  void ShowShadowUnderlay(const gfx::Rect& bounds, float opacity);
+
   // Creates, deletes and update the shadow bounds based on
   // |pending_shadow_content_bounds_|.
   void UpdateShadow();