Revert "Do not percent-encode '&' and ';' in URL queries."

This reverts commit 27eaa9817b9837aa478e0667158292a0295985df.

Reason for revert: brettw would like this to be discussed more widely before landing.

Original change's description:
> Do not percent-encode '&' and ';' in URL queries.
> 
> The URL spec has specified that U+0026 ('&') and U+003B (';') should not be
> percent-encoded since
> https://github.com/whatwg/url/commit/bbeacfe00317554daab0ece983f42692d42487fc,
> so follow suit a few years late and match what Gecko has already been doing.
> 
> Bug: 795733
> Change-Id: Icc28699fc14b63ef92751e81d94fb3eeee876781
> Reviewed-on: https://chromium-review.googlesource.com/829313
> Reviewed-by: Joshua Bell <jsbell@chromium.org>
> Commit-Queue: Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com>
> Cr-Commit-Position: refs/heads/master@{#525101}

TBR=jsbell@chromium.org,brettw@chromium.org,raphael.kubo.da.costa@intel.com,jshin@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 795733
Change-Id: I0c6f0d1163ae2eccfcb108a7ecfb65fd47d61321
Reviewed-on: https://chromium-review.googlesource.com/852500
Commit-Queue: Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com>
Reviewed-by: Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com>
Cr-Commit-Position: refs/heads/master@{#527778}
9 files changed