Add comment-reflow CLs to .git-blame-ignore-revs.

For the following changes:
https://codereview.chromium.org/2390543002/
https://codereview.chromium.org/2390563002/

BUG=563793
NOTRY=true

Review-Url: https://codereview.chromium.org/2386973002
Cr-Commit-Position: refs/heads/master@{#422993}
1 file changed