Add test cases for panel overflow handling.

chrome/browser/ui/panels/base_panel_browser_test.h

Index: chrome/browser/ui/panels/base_panel_browser_test.h
diff --git a/chrome/browser/ui/panels/base_panel_browser_test.h b/chrome/browser/ui/panels/base_panel_browser_test.h
index b45ff14751bb08c408f2fbd5d1b655531c9ee4e8..e82fd47f50aef762d7f1e40f04daee6d6ed96f84 100644
--- a/chrome/browser/ui/panels/base_panel_browser_test.h
+++ b/chrome/browser/ui/panels/base_panel_browser_test.h
@@ -71,6 +71,10 @@ class BasePanelBrowserTest : public InProcessBrowserTest {
                                            Extension::Location location,
                                            const DictionaryValue& extra_value);
 
+  static void MoveMouse(const gfx::Point& position);
+  static void CloseWindowAndWait(Browser* browser);
+  static std::string GetPanelName(int index);
+
   gfx::Rect testing_work_area() const { return testing_work_area_; }
   void set_testing_work_area(const gfx::Rect& work_area) {
     testing_work_area_ = work_area;