Update Panel mininimize/restore button on strip and expansion state change.

chrome/browser/ui/panels/panel_browser_window_gtk.cc

Index: chrome/browser/ui/panels/panel_browser_window_gtk.cc
diff --git a/chrome/browser/ui/panels/panel_browser_window_gtk.cc b/chrome/browser/ui/panels/panel_browser_window_gtk.cc
index 76188e2d7c97101abb4356c8b54345298a969bf6..8d1d3b9f3e9f37dd81bc9638953c6317afea6f63 100644
--- a/chrome/browser/ui/panels/panel_browser_window_gtk.cc
+++ b/chrome/browser/ui/panels/panel_browser_window_gtk.cc
@@ -274,8 +274,6 @@ const gfx::Image* PanelBrowserWindowGtk::GetThemeFrameImage() const {
 void PanelBrowserWindowGtk::DrawCustomFrame(cairo_t* cr,
                                             GtkWidget* widget,
                                             GdkEventExpose* event) {
-  GetPanelTitlebar()->UpdateMinimizeRestoreButtonVisibility();
-
   gfx::CairoCachedSurface* surface = GetThemeFrameImage()->ToCairo();
 
   surface->SetSource(cr, widget, 0, 0);
@@ -471,10 +469,6 @@ void PanelBrowserWindowGtk::EnsurePanelFullyVisible() {
   gtk_window_present(window());
 }
 
-void PanelBrowserWindowGtk::SetPanelAppIconVisibility(bool visible) {
-  return;
-}
-
 void PanelBrowserWindowGtk::SetPanelAlwaysOnTop(bool on_top) {
   gtk_window_set_keep_above(window(), on_top);
 }
@@ -482,6 +476,10 @@ void PanelBrowserWindowGtk::SetPanelAlwaysOnTop(bool on_top) {
 void PanelBrowserWindowGtk::EnableResizeByMouse(bool enable) {
 }
 
+void PanelBrowserWindowGtk::UpdateMinimizeRestoreButtonVisibility() {
+  GetPanelTitlebar()->UpdateMinimizeRestoreButtonVisibility();
+}
+
 gfx::Size PanelBrowserWindowGtk::WindowSizeFromContentSize(
     const gfx::Size& content_size) const {
   return gfx::Size(content_size.width() + frame_size_.width(),