try to deprecate fFlagsMask from SkLayerDrawLooper

We think we want to move around how flags/fields like linearText and strikeThru
are specified. SkPaint has helpers for nearly all of these, but LayerInfo in
the draw looper just exposes the raw bitfield.

On survey of chrome/android, it appears that no one uses those, so it may be
safe to just remove the feature entirely from the looper.

R=bungeman@google.com, scroggo@google.com

Review URL: https://codereview.chromium.org/181433009

git-svn-id: http://skia.googlecode.com/svn/trunk@13607 2bbb7eff-a529-9590-31e7-b0007b416f81
7 files changed