GitLab

ViewManager from mojo_shell. First attempt here:
https://codereview.chromium.org/477923004/

Failed the linux gn dbg build after cq landed:
http://build.chromium.org/p/chromium.linux/builders/Linux%20GN%20%28dbg%29/builds/12251

BUG=
TBR=ben@chromium.org

Review URL: https://codereview.chromium.org/568883003

Cr-Commit-Position: refs/heads/master@{#295230}