reformat run-webkit-tests --driver-logging output to show ctrl chars.

Turns out that if you don't make the nonprintable characters visible,
you'll miss valuable information like whether there are LFs or CRLFs
in your output. This should also make dumping PNG data less likely
to completely mess up your terminal.

Also this patch adds a test for --driver-logging, but disables it
as the mock-ports seem to be somewhat broken at the moment. I'll fix
that issue in a separate bug.

R=ojan@chromium.org
BUG=276728

Review URL: https://chromiumcodereview.appspot.com/23093014

git-svn-id: svn://svn.chromium.org/blink/trunk@156519 bbb929c8-8fbe-4397-9dbb-9b2b20218538