Move jse_define.h to fxjs/xfa directory.

It is XFA-only but was left out of the mass move at
  https://pdfium-review.googlesource.com/c/47133

Rename its wrapper template method from JSMethod to JSEMethod
to match header naming (JSMethod as it turns out, is also the
name of a similar but unrelated template in the non-xfa code).

Change-Id: I68251290df3621d31b7c3d819e12946b5f9ff0bf
Reviewed-on: https://pdfium-review.googlesource.com/c/47391
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
diff --git a/fxjs/BUILD.gn b/fxjs/BUILD.gn
index 4c4df16..a8d850d 100644
--- a/fxjs/BUILD.gn
+++ b/fxjs/BUILD.gn
@@ -100,7 +100,6 @@
       "js_define.h",
       "js_resources.cpp",
       "js_resources.h",
-      "jse_define.h",
     ]
     deps += [
       "../core/fdrm",
@@ -439,6 +438,7 @@
         "xfa/cjx_xsdconnection.h",
         "xfa/fxjse.cpp",
         "xfa/fxjse.h",
+        "xfa/jse_define.h",
       ]
       deps += [ "../xfa/fxfa/fm2js" ]
     }