Run Virtual Me2Me sessions via /etc/X11/Xsession

This is so that the system startup files in /etc/X11/Xsession.d/ are sourced
before running the chosen session.


BUG=139846


Review URL: https://chromiumcodereview.appspot.com/10843011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@149288 0039d316-1c4b-4281-b951-d872f2087c98

remoting/tools/me2me_virtual_host.py

@@ -493,10 +493,11 @@ def choose_x_session():
   # "unity-2d-panel" was chosen here simply because it appears in the TryExec
   # line of the session's .desktop file; other choices might be just as good.
   for test_file, command in [
-    ("/usr/bin/gnome-session-fallback", "/usr/bin/gnome-session-fallback"),
+    ("/usr/bin/gnome-session-fallback",
+      ["/etc/X11/Xsession", "gnome-session-fallback"]),
     ("/etc/gdm/Xsession", "/etc/gdm/Xsession"),
     ("/usr/bin/unity-2d-panel",
-      ["/usr/bin/gnome-session", "--session=ubuntu-2d"]),
+      ["/etc/X11/Xsession", "/usr/bin/gnome-session --session=ubuntu-2d"]),
   ]:
     if os.path.exists(test_file):
       return command