mozilla Fine-tune custom compiler optimizations Use inter-process communication between tabs and plugins. Allows for greater stability in case of plugin crashes Enable JIT for JavaScript using MethodJIT for faster JS performance. Hardened users can disable this USE-flag to use MPROTECT on grsecurity kernels. Add support for profile-guided optimization using gcc-4.5, for faster binaries. This option will double the compile time. Use the system-wide dev-db/sqlite installation with secure-delete enabled Use system libvpx media-libs/libvpx