chromium: Update all channels to latest versions.

With this commit, the following new upstream versions are introduced:

stable: 37.0.2062.94 -> 37.0.2062.120
beta:   38.0.2125.24 -> 38.0.2125.101
dev:    39.0.2138.3  -> 39.0.2171.7

All channels built fine on my machine and were tested against a few
sites.

The missing_alg_import.patch now is no longer needed for version 39, so
we're not applying it there anymore.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>