Enable logging of page redirections.

BUG=388287

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=177320

Review URL: https://codereview.chromium.org/367483005

git-svn-id: svn://svn.chromium.org/blink/trunk@177531 bbb929c8-8fbe-4397-9dbb-9b2b20218538