The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/da2a0e0e0d588ef2ef20b00c6a7ccda01a3f79b8

commit da2a0e0e0d588ef2ef20b00c6a7ccda01a3f79b8
Author: Ryan Sturm <ryansturm@chromium.org>
Date: Thu Oct 25 01:52:21 2018

Converging two Previews methods called from content

Initially, these were called on different threads, but now they can both
be called from the UI thread at the same time. This will allow
re-determining the PreviewsState after a redirect in a future CL.

Bug:  892253 
Change-Id: I072717ccb6f39bd8161aeaae5b76ec8a5834769b
Reviewed-on: https://chromium-review.googlesource.com/c/1297171
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Doug Arnett <dougarnett@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Commit-Queue: Ryan Sturm <ryansturm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602572}
[modify] https://crrev.com/da2a0e0e0d588ef2ef20b00c6a7ccda01a3f79b8/chrome/browser/chrome_content_browser_client.cc
[modify] https://crrev.com/da2a0e0e0d588ef2ef20b00c6a7ccda01a3f79b8/content/browser/frame_host/navigation_controller_delegate.h
[modify] https://crrev.com/da2a0e0e0d588ef2ef20b00c6a7ccda01a3f79b8/content/browser/frame_host/navigation_controller_impl.cc
[modify] https://crrev.com/da2a0e0e0d588ef2ef20b00c6a7ccda01a3f79b8/content/browser/web_contents/web_contents_impl.cc
[modify] https://crrev.com/da2a0e0e0d588ef2ef20b00c6a7ccda01a3f79b8/content/browser/web_contents/web_contents_impl.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/647d1d9d0b4beb0512c50493a10e25adf3dc8007

commit 647d1d9d0b4beb0512c50493a10e25adf3dc8007
Author: Ryan Sturm <ryansturm@chromium.org>
Date: Wed Nov 07 15:41:39 2018

[Previews] Adding redirect evaluations for some preview types

This CL adds a redirect PreviewsState evaluation for all
PreviewsStates that are not used in a URLLoader. Specifically,
Offline, server LoFi, and DRP HTTP Lite Page are not re-evaluated
on a redirect, but all other Preview types are re-evaluated entirely.

Bug:  892253 
Change-Id: If83642658304650b29d01ac727911a9cc75dcbf1
Reviewed-on: https://chromium-review.googlesource.com/c/1308768
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Camille Lamy <clamy@chromium.org>
Commit-Queue: Ryan Sturm <ryansturm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606056}
[modify] https://crrev.com/647d1d9d0b4beb0512c50493a10e25adf3dc8007/chrome/browser/chrome_content_browser_client.cc
[modify] https://crrev.com/647d1d9d0b4beb0512c50493a10e25adf3dc8007/chrome/browser/chrome_content_browser_client.h
[modify] https://crrev.com/647d1d9d0b4beb0512c50493a10e25adf3dc8007/chrome/browser/previews/resource_loading_hints/resource_loading_hints_browsertest.cc
[modify] https://crrev.com/647d1d9d0b4beb0512c50493a10e25adf3dc8007/components/previews/content/previews_content_util.cc
[modify] https://crrev.com/647d1d9d0b4beb0512c50493a10e25adf3dc8007/components/previews/content/previews_content_util.h
[modify] https://crrev.com/647d1d9d0b4beb0512c50493a10e25adf3dc8007/components/previews/content/previews_content_util_unittest.cc
[modify] https://crrev.com/647d1d9d0b4beb0512c50493a10e25adf3dc8007/content/browser/frame_host/navigation_request.cc
[modify] https://crrev.com/647d1d9d0b4beb0512c50493a10e25adf3dc8007/content/browser/navigation_browsertest.cc
[modify] https://crrev.com/647d1d9d0b4beb0512c50493a10e25adf3dc8007/content/public/browser/content_browser_client.cc
[modify] https://crrev.com/647d1d9d0b4beb0512c50493a10e25adf3dc8007/content/public/browser/content_browser_client.h
[modify] https://crrev.com/647d1d9d0b4beb0512c50493a10e25adf3dc8007/tools/metrics/histograms/histograms.xml