GitLab

The dev marker is removed, making this a stable pepper API.

The context around this decision can be found here:
https://groups.google.com/a/chromium.org/forum/#!topic/pepper-dev/Dw-UGrTuYuI

Review URL: https://codereview.chromium.org/547523002

Cr-Commit-Position: refs/heads/master@{#294056}