Linux: call xdg-open on downloaded files to open them.

app/win_util.cc

Index: app/win_util.cc
===================================================================
--- app/win_util.cc	(revision 17020)
+++ app/win_util.cc	(working copy)
@@ -177,8 +177,7 @@
   return false;
 }
 
-bool OpenItemViaShellNoZoneCheck(const FilePath& full_path,
-                                 bool ask_for_app) {
+bool OpenItemViaShellNoZoneCheck(const FilePath& full_path) {
   SHELLEXECUTEINFO sei = { sizeof(sei) };
   sei.fMask = SEE_MASK_NOZONECHECKS | SEE_MASK_FLAG_DDEWAIT;
   sei.nShow = SW_SHOWNORMAL;
@@ -187,7 +186,7 @@
   if (::ShellExecuteExW(&sei))
     return true;
   LONG_PTR error = reinterpret_cast<LONG_PTR>(sei.hInstApp);
-  if ((error == SE_ERR_NOASSOC) && ask_for_app)
+  if ((error == SE_ERR_NOASSOC))
     return OpenItemWithExternalApp(full_path.value());
   return false;
 }