Build fixes for Clang on Windows

See e.g. http://build.chromium.org/p/chromium.fyi/builders/CrWinClang/builds/4502/steps/compile/logs/stdio

BUG=chromium:82385
R=mark@chromium.org

Review URL: https://codereview.chromium.org/1473073008 .

Patch from Hans Wennborg <hans@chromium.org>.
2 files changed