chromeos: Run beforeunload handlers when closing panels.

chrome/browser/chromeos/frame/panel_controller.cc

Index: chrome/browser/chromeos/frame/panel_controller.cc
diff --git a/chrome/browser/chromeos/frame/panel_controller.cc b/chrome/browser/chromeos/frame/panel_controller.cc
index 31f4961fe9237ccd7bd0a03310c682530fac2299..4de770b922b5bed1a168f8c192c065b9f4a56c1e 100644
--- a/chrome/browser/chromeos/frame/panel_controller.cc
+++ b/chrome/browser/chromeos/frame/panel_controller.cc
@@ -306,8 +306,11 @@ void PanelController::Close() {
 void PanelController::OnCloseButtonPressed() {
   DCHECK(title_content_);
   if (title_window_) {
-    if (delegate_)
+    if (delegate_) {
+      if (!delegate_->CanClosePanel())

[oshima, 2011/01/13 21:18:12]

This may not be the scope of this CL, but wouldn't it be better to give visual
feedback that a user can't close the panel?

[Daniel Erat, 2011/01/13 21:26:34]

In the case of a beforeunload handler, a modal dialog is opened.

+        return;
       delegate_->ClosePanel();
+    }
     Close();
   }
 }