The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef

commit 8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef
Author: Findit <findit-for-me@appspot.gserviceaccount.com>
Date: Sat Jan 19 01:45:42 2019

Revert "Portals: Expose portalHost to portal's browsing context"

This reverts commit 9d4738420905a6b28407a8282512d8307d413780.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 624316 as the
culprit for flakes in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/flake/flake-culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyQwsSDEZsYWtlQ3VscHJpdCIxY2hyb21pdW0vOWQ0NzM4NDIwOTA1YTZiMjg0MDdhODI4MjUxMmQ4MzA3ZDQxMzc4MAw

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.memory/WebKit%20Linux%20Trusty%20Leak/29014

Sample Failed Step: webkit_layout_tests

Sample Flaky Test: external/wpt/portals/portals-host-exposure.sub.html

Original change's description:
> Portals: Expose portalHost to portal's browsing context
> 
> window.portalHost returns a PortalHost to script running inside the main
> frame within a portal.
> 
> Bug: 914117
> Change-Id: I26fb4ae9676261bee4446bfbc6ee34b28dc618b1
> Reviewed-on: https://chromium-review.googlesource.com/c/1399569
> Commit-Queue: Adithya Srinivasan <adithyas@chromium.org>
> Reviewed-by: Daniel Cheng <dcheng@chromium.org>
> Reviewed-by: Charlie Reis <creis@chromium.org>
> Reviewed-by: Lucas Gadani <lfg@chromium.org>
> Reviewed-by: Jeremy Roman <jbroman@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#624316}

Change-Id: I38d4e208daafc8381495a4249c02928757bbdfc8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 914117,  923610 
Reviewed-on: https://chromium-review.googlesource.com/c/1423660
Cr-Commit-Position: refs/heads/master@{#624405}
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/content/browser/renderer_host/render_view_host_delegate.cc
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/content/browser/renderer_host/render_view_host_delegate.h
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/content/browser/renderer_host/render_view_host_impl.cc
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/content/browser/web_contents/web_contents_impl.cc
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/content/browser/web_contents/web_contents_impl.h
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/content/common/renderer.mojom
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/content/renderer/render_view_impl.cc
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/third_party/blink/public/web/web_view.h
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/third_party/blink/renderer/core/events/event_target_names.json5
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/third_party/blink/renderer/core/exported/web_view_impl.cc
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/third_party/blink/renderer/core/exported/web_view_impl.h
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/third_party/blink/renderer/core/html/BUILD.gn
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/third_party/blink/renderer/core/html/portal/dom_window_portal_host.cc
[delete] https://crrev.com/d7e08558e23d5cdd19f236f3d6530f21b7fd8c33/third_party/blink/renderer/core/html/portal/portal_host.cc
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/third_party/blink/renderer/core/html/portal/portal_host.h
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/third_party/blink/renderer/core/page/page.cc
[modify] https://crrev.com/8c58c5ecce76b7c8458b2a55dd46fff4d086a9ef/third_party/blink/renderer/core/page/page.h
[delete] https://crrev.com/d7e08558e23d5cdd19f236f3d6530f21b7fd8c33/third_party/blink/web_tests/external/wpt/portals/portals-host-exposure.sub.html
[delete] https://crrev.com/d7e08558e23d5cdd19f236f3d6530f21b7fd8c33/third_party/blink/web_tests/external/wpt/portals/resources/portal-forward-with-broadcast.sub.html
[delete] https://crrev.com/d7e08558e23d5cdd19f236f3d6530f21b7fd8c33/third_party/blink/web_tests/external/wpt/portals/resources/portal-host-cross-origin-navigate.sub.html
[delete] https://crrev.com/d7e08558e23d5cdd19f236f3d6530f21b7fd8c33/third_party/blink/web_tests/external/wpt/portals/resources/portal-host-cross-origin.sub.html
[delete] https://crrev.com/d7e08558e23d5cdd19f236f3d6530f21b7fd8c33/third_party/blink/web_tests/external/wpt/portals/resources/portal-host.html

(Chromium sheriff) Let me close this issue as the patch was reverted.