Revert "Make renderer-initiated navigation to about:blank to use the default path."

This reverts commit 2cd39eb02d017e6ce8db65045d6f13833505963c.

Reason for revert: The branch cut was supposed to be yesterday, but I
haven't received any confirmation is happened. To be sure revert this
commit for the moment.

Original change's description:
> Make renderer-initiated navigation to about:blank to use the default path.
> 
> We used to believe renderer initiated navigation from a document to
> about:blank needed to happen sometimes "synchronously". This isn't the
> case, a PostTask is currently used. The only real requirement is when
> committing the initial empty document.
> 
> This CL makes those navigation to use the default path instead.
> 
> This requires a few tests to be updated:
> 
> 1) The initiator and a few other properties needs to be properly set. There
>    are DCHECK in BeginNavigationInternal to enforce renderer initiated
>    navigation always have a defined initiator.
> 
> 2) runtime-console-log-handle-navigate.js: In console-log-navigate, console.log
>    can use the 'getter' of the object several times (up to 2) to print the
>    object. It triggers several about:blank navigations. Since they are now going
>    to the browser process, they are committed later compared to the script
>    execution. The test became less reliable. The test was using
>    dp.Runtime.onceExecutionContextCreated to wait for new documents to commit,
>    but waiting was started potentially after the event occured. The new test is
>    now creating the Promise before triggering the action that will later resolve
>    it. The action is either creating the iframe or making use of the logXXX()
>    function. This is now fully reliable.
> 
> Bug: 936696
> Change-Id: Ibf1a87f83d2e8bfd621d067f0a29a14a069384a8
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1543258
> Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
> Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
> Reviewed-by: Daniel Cheng <dcheng@chromium.org>
> Reviewed-by: Camille Lamy <clamy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#652493}

TBR=dgozman@chromium.org,dcheng@chromium.org,nasko@chromium.org,clamy@chromium.org,alexmos@chromium.org,arthursonzogni@chromium.org

Change-Id: I6a5fe676275d59027907a1c9540dfe941fab3e18
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 936696
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1574320
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652499}
7 files changed