DM: write failed comparison mode .pngs one more level deep in the tree.

E.g.  instead of having to compare
    /tmp/dm/565/optimizations.png
vs.
    /tmp/dm/replay/optimizations_565.png

it's now

    /tmp/dm/565/optimizations.png
vs.
    /tmp/dm/replay/565/optimizations.png

This lets working with skdiff go a lot more smoothly.

BUG=
R=bsalomon@google.com

Review URL: https://codereview.chromium.org/88773002

git-svn-id: http://skia.googlecode.com/svn/trunk@12402 2bbb7eff-a529-9590-31e7-b0007b416f81
8 files changed