Previously, all extras were "experimental" and left out of the snapshot. This
patch moves them to the snapshot, so now all extras are non-experimental. A
future patch will re-introduce experimental extras as part of the linked bug.

R=yangguo@chromium.org
BUG=https://code.google.com/p/chromium/issues/detail?id=507137
LOG=Y

Review URL: https://codereview.chromium.org/1289603002

Cr-Commit-Position: refs/heads/master@{#30183}