SkRecord bug fixes

Optional arguments to SkCanvas calls leaked refs (but not memory) because we
didn't destruct the optional objects (really, just SkPaint: other optional args
are all POD).  This adds Optional and PODArray, where Optional makes sure to
call the destructor.

I overlooked that SkPictureRecord really does call paint.computeFastBounds().
Do the same in SkRecordDraw.

BUG=skia:2378
R=reed@google.com, mtklein@google.com, tomhudson@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/235983015

git-svn-id: http://skia.googlecode.com/svn/trunk@14197 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed