The default GN build will match that of the host OS (so 64-bit
Windows will give 64-bit builds). The default GYP build is 32-bits
on all Windows variants.
To force 64-bit building in GYP, run the following command prior to
building: python build\gyp_chromium -Dtarget_arch=x64 and use
either the Release_x64 or Debug_x64 build directory with Ninja
(e.g. "ninja -C out\Debug_x64")