Add tiled rendering as an option to GM.

Use an SkGPipe to play back drawing into tiles.
This will help us to debug differences in drawing
while tiled.

Pass --tiledPipe to gm to use the tiled pipe.
Review URL: https://codereview.appspot.com/6295050

git-svn-id: http://skia.googlecode.com/svn/trunk@4199 2bbb7eff-a529-9590-31e7-b0007b416f81
6 files changed