Revert of Pull up a subset of CanvasRenderingContext2D into BaseRenderingContext2D. (patchset #6 id:100001 of https://codereview.chromium.org/1710633002/ )

Reason for revert:
Speculative revert to fix WebKit Win non-Oilpan (dbg) breakage.

Original issue's description:
> Pull up a subset of CanvasRenderingContext2D into BaseRenderingContext2D.
>
> This will allow an additional sub-class of BaseRC2D called PaintRC2D.
> BaseRC2D contains the subset of APIs needed for PaintRC2D.
>
> See: https://drafts.css-houdini.org/css-paint-api/#paintrenderingcontext2d
>
> BUG=578252
>
> Committed: https://crrev.com/4333ef80f90f702a0571c030f15f0e317931ee7d
> Cr-Commit-Position: refs/heads/master@{#377082}

TBR=junov@chromium.org,sigbjornf@opera.com,ikilpatrick@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
BUG=578252

Review URL: https://codereview.chromium.org/1732923002

Cr-Commit-Position: refs/heads/master@{#377348}
5 files changed