This is happening as part of https://chromium-review.googlesource.com/c/chromium/src/+/648349

The new recorded page shows a login screen overlaid on top of what looks like an animated scrolling set of... pins?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/71d0b6e55036e66e74dde48b1c7d5364eb1e5b1d

commit 71d0b6e55036e66e74dde48b1c7d5364eb1e5b1d
Author: Walter Korman <wkorman@chromium.org>
Date: Sat Sep 02 15:02:07 2017

New web page recordings for various Top 25 pages.

Re-record Top 25 page set to incorporate updated versions of broken
pages, in particular:

Google sites that were failing login and/or hitting DCHECK:
- Calendar (recording here is still broken, see
   http://crbug.com/761572  for more)
- Image Search
- Docs
- Plus
- YouTube
- Gmail

Facebook Barack Obama page was failing login. Fixing to use new
login method produces a page with no content since the test account
can't view page content for some known and expected reason. So I
changed Facebook story to act as logged-out which can at least see
the content though it's perhaps less representative of a real user.

Blogger and WordPress story recordings are still broken here, see
 http://crbug.com/761440 .

http://games.yahoo.com looks like it's recording a redirect to what
looks like plain Yahoo News or home page. Harmless but perhaps
redundant.

Other changes to follow shortly to fix login logic for Google and
Facebook sites and DCHECK issues properly, but having updated
recordings in meantime seems worthwhile despite hackery required to
accomplish.

Steps taken to re-record:
- comment out DCHECK in LayoutTableBoxComponent.cpp:45  http://crbug.com/761434 
- comment out DisableStory for mail.google.com and CNN in
  tools/perf/benchmarks/rasterize_and_record_micro.py
- comment out DCHECK in rasterize_and_record_benchmark.cc:99  http://crbug.com/761510 

% tools/perf/record_wpr --story top25_page_set \
    rasterize_and_record_micro_top25
% upload_to_google_storage.py --bucket=chrome-partner-telemetry \
    tools/perf/page_sets/data/top_25_009.wprgo

Bug:  756117 ,  757601 
Change-Id: I67f6226173bccdea8cdb2a377d023d1dc18438d6
Reviewed-on: https://chromium-review.googlesource.com/648349
Commit-Queue: Walter Korman <wkorman@chromium.org>
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Cr-Commit-Position: refs/heads/master@{#499396}
[modify] https://crrev.com/71d0b6e55036e66e74dde48b1c7d5364eb1e5b1d/tools/perf/page_sets/data/top_25.json
[add] https://crrev.com/71d0b6e55036e66e74dde48b1c7d5364eb1e5b1d/tools/perf/page_sets/data/top_25_009.wprgo.sha1