Fix preprocessor conditional for in_process_browser_test.

X11 includes should be guarded by USE_X11, not OS_LINUX.

Change-Id: I4a5e666bbb01ddb41861d26b9cf999c8cc1e08a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2419006
Commit-Queue: Erik Chen <erikchen@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Auto-Submit: Erik Chen <erikchen@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#808519}

chrome/test/base/in_process_browser_test.cc

@@ -106,7 +106,7 @@
 #include "ui/events/test/event_generator.h"
 #endif  // defined(OS_CHROMEOS)
 
-#if !defined(OS_CHROMEOS) && defined(OS_LINUX)
+#if !defined(OS_CHROMEOS) && defined(USE_X11)
 #include "ui/views/test/test_desktop_screen_x11.h"
 #endif