windows – Bad performance of Chromium after compiling

As Asesh correctly noted, the problem was in debug mode. But adding key “is_debug=false” to gn gen command is not enough. The best solution will be the adding “is_official_build=true” key. Here is description:

is_official_build
    Current value (from the default) = false
      From //build/config/BUILDCONFIG.gn:136

    Set to enable the official build level of optimization. This has nothing
    to do with branding, but enables an additional level of optimization above
    release (!is_debug). This might be better expressed as a tri-state
    (debug, release, official) but for historical reasons there are two
    separate flags.

    IMPORTANT NOTE: (!is_debug) is *not* sufficient to get satisfying
    performance. In particular, DCHECK()s are still enabled for release builds,
    which can halve overall performance, and do increase memory usage. Always
    set "is_official_build" to true for any build intended to ship to end-users.

Thanks Asesh for pointing me in the right direction.