Summary:
- Add CSSLayoutSetMemoryFuncs function which allows application to replace malloc, calloc, realloc and free with application's functions, like zalloc and zfree of zlib.
- Fixed memory leaks in tests.
- Close#247
For example, to use dlmalloc with USE_DL_PREFIX
CSSLayoutSetMemoryFuncs(&dlmalloc, &dlcalloc, &dlrealloc, &dlfree);
Reviewed By: emilsjolander
Differential Revision: D4178386
fbshipit-source-id: a79dbdaf82a512f42cc43f99dbc49faba296903b
