gl: x11: Remove not used includes for X11.

We have cleaned up ui/gl from USE_X11. These includes are not
needed anymore.

TBR=backer@chromium.org

Bug: 1036285
Change-Id: I6420b774a6a190527f76ab3fa5cb058b54d76a7a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2144136Reviewed-by: Maksim Sisov <msisov@igalia.com>
Commit-Queue: Maksim Sisov <msisov@igalia.com>
Cr-Commit-Position: refs/heads/master@{#758167}

ui/gl/gl_surface_egl.cc

@@ -38,12 +38,6 @@
 #include "ui/gl/scoped_make_current.h"
 #include "ui/gl/sync_control_vsync_provider.h"
 
-#if defined(USE_X11)
-#include "ui/base/x/x11_display_util.h"
-#include "ui/base/x/x11_util_internal.h"  // nogncheck
-#include "ui/gfx/x/x11.h"
-#endif
-
 #if defined(OS_ANDROID)
 #include <android/native_window_jni.h>
 #include "base/android/build_info.h"