Revert "Forms: Add a UseCounter for opening popups while a file chooser is opening"

This reverts commit 0b46e1db3d88b762411614d6ae7bbe4f1d5cd6e0.

Reason for revert: Causing multiple layout tests failed based on findit.

Original change's description:
> Forms: Add a UseCounter for opening popups while a file chooser is opening
> 
> We'd like to fix a confusing UI issue, and to know the impact
> of a possible fix.
> 
> Bug: 637639
> Change-Id: I7af67ac314f61723c7904cf0fee408ac2b60e774
> Reviewed-on: https://chromium-review.googlesource.com/1139940
> Commit-Queue: Kent Tamura <tkent@chromium.org>
> Reviewed-by: Keishi Hattori <keishi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#575575}

TBR=keishi@chromium.org,tkent@chromium.org

Change-Id: I4bd3877c33ea7a70a7a7d0d53b7cbb1411240da3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 637639
Reviewed-on: https://chromium-review.googlesource.com/1140393
Reviewed-by: Owen Min <zmin@chromium.org>
Commit-Queue: Owen Min <zmin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575643}
7 files changed