Rebase WebAudio codec-tests on Win after ffmpeg roll.

BUG=
R=dalecurtis@chromium.org
TBR=dalecurtis@chromium.org

I verified that the update changed the expected results by at most 1
lsb, so no major change in the codecs in this ffmpeg update.

Review URL: https://codereview.chromium.org/64923003

git-svn-id: svn://svn.chromium.org/blink/trunk@161566 bbb929c8-8fbe-4397-9dbb-9b2b20218538