Now that Jellybean is deprecated the code in RealSizeEstimate https://cs.chromium.org/chromium/src/base/allocator/allocator_shim_default_dispatch_to_linker_wrapped_symbols.cc?q=allocator_shim_default_dispatch_to_linker_wrapped_symbols.cc&sq=package:chromium&dr&l=71 can be cleaned up. While clean-up is happening, it should also be looked into whether malloc_usable_size was correctly hooked in the original change as the symbol isn't present in //base/allocator/BUILD.gn:wrap_malloc_symbols and I'm not sure it's correctly wired up.

(This may affect cronet, needs to be investigated whether to contact them as per https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/yfUWtN3Dehw)