Make fxjs/ pass gn check.

Use allow_circular_includes_from as a crutch for now.

Change-Id: I8c53bafd864048506a77354f57e27cac50369005
Reviewed-on: https://pdfium-review.googlesource.com/c/43989
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/.gn b/.gn
index 764e08c..8dc9f60 100644
--- a/.gn
+++ b/.gn
@@ -20,6 +20,7 @@
   "//core/fxcrt/*",
   "//fpdfsdk/*",
   "//fxbarcode/*",
+  "//fxjs/*",
   "//samples/*",
   "//testing/:*",
   "//testing/fuzzers/*",
@@ -28,5 +29,4 @@
 
   # TODO(thestig): Work on these.
   #"//core/*",
-  #"//fxjs/*",
 ]