Increase Windows XP hardware buffer size to 4096.

In local testing with XP we noticed WebAudio and HTML5 suffer from
clicking with the "low latency" 2048 buffer size.

This CL also adds a --audio-buffer-size parameter which we can use
to have users tweak in the field and report results back.

BUG=161307
TEST=XP!
TBR=sky

Review URL: https://codereview.chromium.org/11309015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@168111 0039d316-1c4b-4281-b951-d872f2087c98
6 files changed