abseil-cpp needs to carry the absl.pc.in file and the ebuild is modified to use that to generate and install a pkg-config metadata file for the package. This is needed for libchrome to be inspected by pkg-config.
Due to b/184603259, a workaround in the ebuild is needed to replace instances of absl:: with absl::ABSL_OPTION_INLINE_NAMESPACE_NAME:: to prevent name conflicts.