Move FxFreeDeleter to fx_memory_wrappers.h

Then fix IWYU and add a simple test.

Change-Id: Ib75f4593506d098da03771cdaaeed8e64d7a50ce
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/62610
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
diff --git a/fxbarcode/cbc_code39.cpp b/fxbarcode/cbc_code39.cpp
index d9dc106..2138d18 100644
--- a/fxbarcode/cbc_code39.cpp
+++ b/fxbarcode/cbc_code39.cpp
@@ -23,6 +23,7 @@
 
 #include <memory>
 
+#include "core/fxcrt/fx_memory_wrappers.h"
 #include "fxbarcode/oned/BC_OnedCode39Writer.h"
 #include "third_party/base/ptr_util.h"