Fix the problem that notifications and panels overlap.

chrome/browser/ui/panels/base_panel_browser_test.cc

Index: chrome/browser/ui/panels/base_panel_browser_test.cc
diff --git a/chrome/browser/ui/panels/base_panel_browser_test.cc b/chrome/browser/ui/panels/base_panel_browser_test.cc
index 037a52f5f4fbfb4281267e882b77d79ff0cebd43..6cb2e36f10c78df23a62ffc7898987b39dfb84ac 100644
--- a/chrome/browser/ui/panels/base_panel_browser_test.cc
+++ b/chrome/browser/ui/panels/base_panel_browser_test.cc
@@ -174,7 +174,12 @@ void BasePanelBrowserTest::SetUpOnMainThread() {
   mock_auto_hiding_desktop_bar_ = new MockAutoHidingDesktopBarImpl(
       panel_manager);
   panel_manager->set_auto_hiding_desktop_bar(mock_auto_hiding_desktop_bar_);
-  panel_manager->SetWorkAreaForTesting(testing_work_area_);
+  // The subclass might override testing_work_area_ to make it empty so that
+  // we will not provide our own testing work area. This is used in testing
+  // the interaction with desktop notification which does not have testing
+  // working area hook up.
+  if (!testing_work_area_.IsEmpty())
+    panel_manager->SetWorkAreaForTesting(testing_work_area_);
   panel_manager->enable_auto_sizing(false);
   panel_manager->remove_delays_for_testing();
   // This is needed so the subsequently created panels can be activated.