Update skia::RefPtr documentation to use std::move() instead of Pass.
Update skia::RefPtr documentation to use std::move() instead of Pass.

R=fmalita@chromium.org
BUG=557422

Review URL: https://codereview.chromium.org/1526643003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#365233}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk