Run ContentMain in a browser_test's browser process. This removes duplication of code in the browse…

ui/views/test/ui_controls_factory_desktop_aurax11.cc

Index: ui/views/test/ui_controls_factory_desktop_aurax11.cc
===================================================================
--- ui/views/test/ui_controls_factory_desktop_aurax11.cc	(revision 257432)
+++ ui/views/test/ui_controls_factory_desktop_aurax11.cc	(working copy)
@@ -314,6 +314,8 @@
 }  // namespace
 
 UIControlsAura* CreateUIControlsDesktopAura() {
+  // The constructor of UIControlsDesktopX11 needs XInitThreads to be called.
+  XInitThreads();
   return new UIControlsDesktopX11();
 }