Revert of Extract WebGraphicsContext3DImpl from webkit/common/gpu. (patchset #12 id:220001 of https://codereview.chromium.org/761243002/)

Reason for revert:
Suspecting as cause for Win8 GN compile fail

Original issue's description:
> Extract WebGraphicsContext3DImpl from webkit/common/gpu.
>
> We decided that it should be fine to move it to gpu/blink now, similar
> to gpu/skia_bindings and cc/blink.
>
> BUG=338338
> TEST=links
> R=piman@chromium.org,jamesr@chromium.org
> TBR=
>
> Committed: https://crrev.com/a962b5f152a0a331bc2e1a5a0d4d38e8adece10d
> Cr-Commit-Position: refs/heads/master@{#306957}

TBR=jamesr@chromium.org,piman@chromium.org,tfarina@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=338338

Review URL: https://codereview.chromium.org/763963003

Cr-Commit-Position: refs/heads/master@{#306985}
20 files changed