remvoe duplicate impl for SkImageInfo flattening

Revert "Revert "PixelRef now returns (nearly) everything that is currently in SkBitmap. The goal is to refactor bitmap later to remove redundancy, and more interestingly, remove the chance for a disconnect between the actual (pixelref) rowbytes and config, and the one claimed by the bitmap.""""""

This reverts commit eabd6b2ed4e494b323c08f32358f45950a0368c3.

BUG=

Review URL: https://codereview.chromium.org/108773003

git-svn-id: http://skia.googlecode.com/svn/trunk@12624 2bbb7eff-a529-9590-31e7-b0007b416f81
36 files changed