cc/paint: Remove cc::PaintSurface.

The callers can now use SkiaPaintCanvas::CreateRasterZeroed to create
a raster canvas.

TBR=bauerb@chromium.org,dalecurtis@chromium.org
BUG=703320
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2764633002
Cr-Commit-Position: refs/heads/master@{#459894}
24 files changed