Remove DEFINE_BASICSHAPE_TYPE_CASTS use from style_path.h

The primary motivation of this CL is to replace |ToStylePath| with
|To<StylePath>|.

This CL also ports other dependent files to refer to a new template
function name.

Bug: 891908
Change-Id: I7682da3cdaddf48008317099c84babe97d63df72
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1534898
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Abhijeet Kandalkar <abhijeet@igalia.com>
Cr-Commit-Position: refs/heads/master@{#643293}
5 files changed