Add test cases for panel overflow handling.

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 ea53bfce947407ef2ee33396e676231017d72206..71e55da628e6bf34677bedf181b99932e2c33cb9 100644
--- a/chrome/browser/ui/panels/panel_manager.cc
+++ b/chrome/browser/ui/panels/panel_manager.cc
@@ -230,8 +230,13 @@ int PanelManager::num_panels() const {
   return panel_strip_->num_panels() + panel_overflow_strip_->num_panels();
 }
 
-const PanelManager::Panels& PanelManager::panels() const {
-  return panel_strip_->panels();
+std::vector<Panel*> PanelManager::panels() const {
+  std::vector<Panel*> panels = panel_strip_->panels();
+  for (PanelOverflowStrip::Panels::const_iterator iter =
+           panel_overflow_strip_->panels().begin();
+       iter != panel_overflow_strip_->panels().end(); ++iter)
+    panels.push_back(*iter);
+  return panels;
 }
 
 void PanelManager::SetMouseWatcher(PanelMouseWatcher* watcher) {