Begin making SkPerlinNoiseShader const.

The overall goal is to make SkShader itself immutable (BUG=skia:1976).
The fields cannot yet be made constant, due to the constructor which
takes an SkReadBuffer. Other than that constructor, the fields are now
unchanged.

Remove setTileSize and initPaint. Merge initPaint with the constructor
of PaintingData, since it is only ever used on a new PaintingData.
Merge setTileSize with the SkPerlinNoiseShader constructor, its only
call site.

BUG=skia:1976
R=reed@google.com, sugoi@google.com, dominikg@chromium.org, senorblanco@google.com, senorblanco@chromium.org

Author: scroggo@google.com

Review URL: https://codereview.chromium.org/169973002

git-svn-id: http://skia.googlecode.com/svn/trunk@13682 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed