Call SkGraphics::Init for in-process V2
Call SkGraphics::Init for in-process V2

Previous attempt called SkGraphics::Init in renderer init, which races
with browser side code that uses skia.

Also noticed that nothing ever calls SkGraphics::Init on browser side,
so this patch calls it in browser process init.

For single-process, RendererMain doesn't run, so SkGraphics::Init is
called once. For multi-process, SkGraphics::Init is not called in both
browser and renderer processes.

BUG=525844
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_tsan_rel_ng

Review URL: https://codereview.chromium.org/1336673002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#348223}

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