(I worked on Linux Chrome back in the era when this change was made.) 64-bit was important on Linux because the system libraries that Chrome uses were increasi

(I worked on Linux Chrome back in the era when this change was made.) 64-bit was important on Linux because the system libraries that Chrome uses were increasingly unavailable in 32-bit versions on 64-bit systems. On other platforms, while there are advantages to 64-bit binaries, those advantages haven't outweighed the other useful things you could be spending engineering time on.