Move IN_OVERFLOW from Panel::ExpansionState to new enum.

chrome/browser/ui/panels/panel_browser_frame_view.cc

Index: chrome/browser/ui/panels/panel_browser_frame_view.cc
diff --git a/chrome/browser/ui/panels/panel_browser_frame_view.cc b/chrome/browser/ui/panels/panel_browser_frame_view.cc
index 9e92767389b4ffb13c34db1b63966bed4c086b90..decb2e33970e5918b4f87727c1b77580ab75a9eb 100644
--- a/chrome/browser/ui/panels/panel_browser_frame_view.cc
+++ b/chrome/browser/ui/panels/panel_browser_frame_view.cc
@@ -494,7 +494,7 @@ void PanelBrowserFrameView::Layout() {
   bool show_close_button = true;
   bool show_settings_button = true;
   bool show_title_label = true;
-  if (panel_browser_view_->panel()->expansion_state() == Panel::IN_OVERFLOW) {
+  if (panel_browser_view_->panel()->layout_state() == Panel::IN_OVERFLOW) {
     if (width() <= IconOnlyWidth()) {
       show_close_button = false;
       show_settings_button = false;
@@ -865,7 +865,7 @@ void PanelBrowserFrameView::UpdateSettingsButtonVisibility(
   DCHECK(has_settings_button_);
 
   // The settings button is not shown in the overflow state.
-  if (panel_browser_view_->panel()->expansion_state() == Panel::IN_OVERFLOW)
+  if (panel_browser_view_->panel()->layout_state() == Panel::IN_OVERFLOW)
     return;
 
   bool is_settings_button_visible = focused || cursor_in_view;