Maybe trigger LitePageRedirect previews on every redirect

Previously triggering was not being checked when the navigation's
PreviewState didn't have LITE_PAGE_REDIRECT set at the start of the
navigation.

This CL fixes the bug by including the NavigationThrottle on every
navigation and checking PreviewsState every time.

Bug: 931939
Change-Id: Ia147e610500ce936a5327cc4004fbd118dfbd2c6
Reviewed-on: https://chromium-review.googlesource.com/c/1473394
Commit-Queue: Robert Ogden <robertogden@chromium.org>
Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#632450}
5 files changed