Revert "Initial: Deferred cross-document commit"

[chromium-wpt-export-bot]

This reverts commit e79f55877ef7b26643b20eaa5a7b5c241135f4bf.

Reason for revert: defer-back.html is flaky on Mac
https://ci.chromium.org/ui/p/chromium/builders/ci/mac15-x64-rel-tests/13194/overview

Original change's description:

Initial: Deferred cross-document commit

Allows the navigation API to defer a cross-document same-origin commit.
See emerging spec at whatwg/html#11819

This CL implements the following:
navigateEvent.deferPageSwap({handler}).

When such handlers are present, they are called, and their returned
promises are used to defer a same-origin cross-document navigation
commit, without intercepting it into a same-document navigation.

This only works for push/replace navigations.

Design:

• A NavigationRequest can now receive an optional mojo
  Receiver with a "Resume" function.
• The navigate event creates a remote for that receiver, and calls
  "Resume" when the deferring promises are resolved.
• This receiver is passed through the BeginNavigation pipeline.
• The above ensures that a particular navigate event is bound only
  to the navigation request it initiated, to avoid races.
• A new CommitDeferringCondition is waiting on that "Resume" call.
  The browser process also verifies that this is a same-origin
  navigation.

This is the first and most basic step. Next steps:

• the handler can register a "restore" callback, which is called if the
  navigation is cancelled or if the page is restored from BFCache.
• deferPageSwap should accept a "historyChange" option, allowing the
  history to be committed (like a pushState) immediately to avoid
  confusion with the back button.
• When commit is deferred, it should also trigger a last minute
  prerender, and defer until the prerendered page is ready (no pending
  render-blocking resources).
• navigateEvent.destination.ready should return true for BFCached pages
  and also for prerendered pages without pending render-blocking
  resources.

(This is all available in a design doc that can be shared upon request).

Chromestatus: https://chromestatus.com/feature/5568746374692864
Bug: 469466893
Change-Id: I6c9064175104a3f3b25f2a1a31af741f72fad9cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7207394
Reviewed-by: Nate Chapin <[email protected]>
Reviewed-by: Nasko Oskov <[email protected]>
Reviewed-by: Dominic Farolino <[email protected]>
Commit-Queue: Noam Rosenthal <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1576467}

Bug: 469466893
Change-Id: I12518d2af09b67da3a10d8f12dcd9f64032af497

Reviewed-on: https://chromium-review.googlesource.com/7531616
WPT-Export-Revision: 61e2f82ac4e43d16b90a512b67624b9ae2fcdd1d