Set orphans and widows to 1 in lots-of-text-balanced multicol performance test.

https://codereview.chromium.org/1909233002 changed the initial values for
orphans and widows to match the spec. This could very well affect performance
slightly, although I cannot reproduce it myself. Speculatively set
orphans/widows to 1 and see if that helps. Add a new test that uses higher
values for orphans and widows, so that we still get to test that too.

BUG=606262

Review-Url: https://codereview.chromium.org/1964473003
Cr-Commit-Position: refs/heads/master@{#392625}
2 files changed