A lot of time has been spent on optimizing Chrome's build: - Ninja build system will perfectly parallelize the build without overloading resources (modulo this OS bug) - Meta-build system was recently completely replaced (gyp-> gn) to improve builds - Lots of work on clang-cl to allow compiling Chrome for Windows without using Microsoft's compiler - Distributed build system to further increase parallelism

So, lots of work has been done to deal with the build times. And probably not a lot of low hanging fruit to be found. But, still more work is being done. Support is being added for 'jumbo' builds (aka unity builds, where multiple translation units are #included into one) which is helping a bit with compile and link times.