Revert "Revert "Reland: Remove SkLights include from SkCanvas.h""

Revert "Revert "Reland: Remove SkLights include from SkCanvas.h""

This reverts commit 9d5f66d9c21eda7d3e2ed47654180c0c4b6e38b1.

Reason for revert: Leon landed Android fixes.

Original change's description:
> Revert "Reland: Remove SkLights include from SkCanvas.h"
>
> This reverts commit fed00319c9bafa41c8df658708030c072b301a41.
>
> Reason for revert: breaking the Android roll.
>
> Original change's description:
> > Reland: Remove SkLights include from SkCanvas.h
> >
> > SkLights.h pulls in a bunch of other headers and is not needed (fwdecl
> > works fine).
> >
> > Change-Id: I3ed97cd7861e51dcb7cfa7950a97b420dbc6fbfb
> > TBR=reed@google.com
> > Reviewed-on: https://skia-review.googlesource.com/15143
> > Commit-Queue: Florin Malita <fmalita@chromium.org>
> > Reviewed-by: Florin Malita <fmalita@chromium.org>
> >
>
> TBR=fmalita@chromium.org,reed@google.com
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
>
> Change-Id: I3b0e69f1d04d160f16a5567b09982d35cc9ca84e
> Reviewed-on: https://skia-review.googlesource.com/15195
> Reviewed-by: Florin Malita <fmalita@chromium.org>
> Commit-Queue: Florin Malita <fmalita@chromium.org>
>

TBR=msarett@google.com,reviews@skia.org,fmalita@chromium.org,reed@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I0a1c2f9df61f16987ab72dfb4f3a205fbcc37667
Reviewed-on: https://skia-review.googlesource.com/15229
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>