Refactor SkRecord opts, converting playback optimizations where possible.

Refactor SkRecord opts, converting playback optimizations where possible.

This adds back two optimizations from SkPicture: drawPosText strength reduction to drawPosTextH, and pointless save-foo-restore blocks are noop'd away.

The small-T optimization in SkRecord gets in the way of implementing replace(), so I removed it.

Just to keep the API focused, I removed the methods on SkRecord that iterate over i for you; it's just as efficient to do it yourself, and all of the interesting code does its own custom iteration.

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

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/245853002

git-svn-id: http://skia.googlecode.com/svn/trunk@14300 2bbb7eff-a529-9590-31e7-b0007b416f81