Fixes possible crash in bookmark menus. Specifically if you had a menu...

views/controls/menu/chrome_menu.cc

Index: views/controls/menu/chrome_menu.cc
===================================================================
--- views/controls/menu/chrome_menu.cc	(revision 22055)
+++ views/controls/menu/chrome_menu.cc	(working copy)
@@ -1790,7 +1790,7 @@
 
   bool open_submenu = false;
   if (!part.menu) {
-    part.menu = source->GetMenuItem();
+    part.menu = part.parent;
     open_submenu = true;
   } else {
     if (part.menu->GetDelegate()->CanDrag(part.menu)) {
@@ -2339,6 +2339,8 @@
     View::ConvertPointToView(NULL, menu, &menu_loc);
     part->menu = GetMenuItemAt(menu, menu_loc.x(), menu_loc.y());
     part->type = MenuPart::MENU_ITEM;
+    if (!part->menu)
+      part->parent = menu->GetMenuItem();
     return true;
   }