Directly include Skia headers where needed.
Directly include Skia headers where needed.

A propsed Skia change will forward declare more types. The changes
in this CL are needed so that ui/views will continue to compile on
Mac after the Skia change.

Review URL: https://codereview.chromium.org/1272693002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#341968}

ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend