Add overflow indicator count on Windows.

chrome/browser/ui/panels/panel_manager.cc

Index: chrome/browser/ui/panels/panel_manager.cc
diff --git a/chrome/browser/ui/panels/panel_manager.cc b/chrome/browser/ui/panels/panel_manager.cc
index 5b34d71b18d0ee71e2741f7649543e99230ca4f1..e0a99625a1e34014567800848a68db347af95de4 100644
--- a/chrome/browser/ui/panels/panel_manager.cc
+++ b/chrome/browser/ui/panels/panel_manager.cc
@@ -186,6 +186,11 @@ void PanelManager::OnPanelExpansionStateChanged(
     panel_strip_->OnPanelExpansionStateChanged(panel, old_state);
 }
 
+void PanelManager::OnPanelAttentionStateChanged(Panel* panel) {
+  if (panel->expansion_state() == Panel::IN_OVERFLOW)
+    panel_overflow_strip_->OnPanelAttentionStateChanged(panel);
+}
+
 void PanelManager::OnPreferredWindowSizeChanged(
     Panel* panel, const gfx::Size& preferred_window_size) {
   if (!auto_sizing_enabled_)