Percent-encode illegal characters in Android page info popup URL

This prevents whitespace and non-ASCII characters from being displayed in
the url, stopping attacks where a carefully crafted URL can be used
to display a message in the popup.

BUG=466351

Review URL: https://codereview.chromium.org/1011383005

Cr-Commit-Position: refs/heads/master@{#322296}
2 files changed