Move IN_OVERFLOW from Panel::ExpansionState to new enum.

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 25ca6e03d0f6a2f888d86b3aca01a03ff8b0d9ba..906a40cda259f76dcaff50aa82075ffb15bcd80e 100644
--- a/chrome/browser/ui/panels/panel_manager.cc
+++ b/chrome/browser/ui/panels/panel_manager.cc
@@ -178,13 +178,20 @@ void PanelManager::EndDragging(bool cancelled) {
   panel_strip_->EndDragging(cancelled);
 }
 
-void PanelManager::OnPanelExpansionStateChanged(Panel* panel) {
-  panel_strip_->OnPanelExpansionStateChanged(panel);
-  panel_overflow_strip_->OnPanelExpansionStateChanged(panel);
+void PanelManager::OnPanelLayoutStateChanged(Panel* panel,
+                                             Panel::LayoutState old_state) {
+  panel_strip_->OnPanelLayoutStateChanged(panel, old_state);
+  panel_overflow_strip_->OnPanelLayoutStateChanged(panel, old_state);
+}
+
+void PanelManager::OnPanelExpansionStateChanged(
+    Panel* panel, Panel::ExpansionState old_state) {
+  DCHECK_EQ(Panel::DOCKED, panel->layout_state());
+  panel_strip_->OnPanelExpansionStateChanged(panel, old_state);
 }
 
 void PanelManager::OnPanelAttentionStateChanged(Panel* panel) {
-  if (panel->expansion_state() == Panel::IN_OVERFLOW)
+  if (panel->layout_state() == Panel::IN_OVERFLOW)
     panel_overflow_strip_->OnPanelAttentionStateChanged(panel);
 }