remove some dead visual studio < 2013 code

We only support building for windows with Visual Studio 2013 Update 4
now, so let's remove dead code that is only used for older Visual
Studio versions.

BUG=442035,158570

Review URL: https://codereview.chromium.org/798163004

Cr-Commit-Position: refs/heads/master@{#309187}
11 files changed