Revert "Prevent WebApps from overwriting document PiP windows initial size"

This reverts commit 9951ee806b565ec36f8a7d6f74fadc84ead9cabd.

Reason for revert: 

AppBrowserDocumentPictureInPictureBrowserTest.AppWindowWebContentsSizeUnchangedAfterExitPip
test is failing.
Step "browser_tests (retry shards) on Mac-13" failing on builder "chromium/ci/Mac13 Tests"


List of failed builders:

Builder: Mac13 Tests
https://ci.chromium.org/p/chromium/builders/ci/Mac13%20Tests
First failing build:
https://ci.chromium.org/p/chromium/builders/ci/Mac13%20Tests/b8744024145780147457

Original change's description:
> Prevent WebApps from overwriting document PiP windows initial size
>
> This change updates `AppBrowserController::OnReceivedInitialURL` to
> ignore document picture in picture windows, since these bounds are
> calculated and set by the `PictureInPictureBrowserFrameView`.
>
> This fixes a bug where the requested PiP window inner size would not be
> honored.
>
> Bug: 348476064, 41459774
> Change-Id: I19bba8b5383c48db4f04052af21917a60857d619
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5656392
> Commit-Queue: Benjamin Keen <bkeen@google.com>
> Reviewed-by: Frank Liberato <liberato@chromium.org>
> Reviewed-by: Daniel Murphy <dmurph@chromium.org>
> Reviewed-by: Chase Phillips <cmp@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1320089}

Bug: 348476064, 41459774, 349694499
Change-Id: If21c0ad3da794084af8e6e9ed9bcaa83662c2f6a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5662336
Auto-Submit: Rakina Zata Amni <rakina@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Owners-Override: Rakina Zata Amni <rakina@chromium.org>
Commit-Queue: Benjamin Keen <bkeen@google.com>
Reviewed-by: Benjamin Keen <bkeen@google.com>
Cr-Commit-Position: refs/heads/main@{#1320136}