Introduce new test for bookmark loading.

BUG=110020

Committed: https://crrev.com/50567ebbd5ca2ff79d87382addc11d25658776d2
Cr-Commit-Position: refs/heads/master@{#312076}

Review URL: https://codereview.chromium.org/840493002

Cr-Commit-Position: refs/heads/master@{#313198}
5 files changed