Revert of Use xvfb with Ozone CrOS.

ui/gl/BUILD.gn

Index: ui/gl/BUILD.gn
diff --git a/ui/gl/BUILD.gn b/ui/gl/BUILD.gn
index 073f687803e6a6707c46150f397197350c80397f..a1f9c69511a6264fbea29bb938c2a3d32219820b 100644
--- a/ui/gl/BUILD.gn
+++ b/ui/gl/BUILD.gn
@@ -408,6 +408,26 @@
   ]
 }
 
+# Non-Ozone trybots end up trying to build this when building "all" and failing
+# when X11 isn't there.
+if (ozone_platform_x11) {
+  group("gl_unittests_ozonex") {
+    testonly = true
+    data_deps = [
+      ":gl_unittests",
+    ]
+  }
+
+  # TODO(GYP_GONE): Delete this after we've converted everything to GN.
+  # The _run targets exist only for compatibility w/ GYP.
+  group("gl_unittests_ozonex_run") {
+    testonly = true
+    deps = [
+      ":gl_unittests_ozonex",
+    ]
+  }
+}
+
 if (is_android) {
   generate_jar_jni("surface_jni_headers") {
     jni_package = "ui/gl"