Remove SkRecorder's kWriteOnly mode.

I'm soon going to have SkRecorder start calling getTotalMatrix(), which
would be broken in write-only mode.  That change is big and nebulous,
but it's clear kWriteOnly needs to go, so we might as well kill it now.

My notes in bench_playback about kWriteOnly mode being important were
probably overly cautious.  I now think this is a fair enough comparison
even re-recording into a read-write canvas.

BUG=skia:2378
R=fmalita@chromium.org, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/290653004

git-svn-id: http://skia.googlecode.com/svn/trunk@14963 2bbb7eff-a529-9590-31e7-b0007b416f81
10 files changed