Noticed this when looking for conspicuous string literals as part of  bug 778067 .

Strings like: "bool OT::ClassDef::sanitize(OT::hb_sanitize_context_t *) const"
Which is from: third_party/harfbuzz-ng/src/hb-ot-layout.cc (.rodata=58.6kb)

They appear to be for debug macros here:
https://cs.chromium.org/chromium/src/third_party/harfbuzz-ng/src/hb-open-type-private.hh?rcl=1c9a9733195266afce1706a22de3bc740bd6fbf8&l=180

And so presumably should not be included in release builds.