Pass SkiaImageFilterBuilder& to FilterEffect::createImageFilter

The builder should never be null, so just make it a reference.

Drop the builder arguments on SVGFEImage::createImageFilterForLayoutObject
because it's unused, and make the LayoutObject& const while touching those
lines.

Make createImageFilter overrides private.

Review URL: https://codereview.chromium.org/1387573003

Cr-Commit-Position: refs/heads/master@{#352543}
39 files changed