Bug 1966586 - Reuse other browser windows when opening _blank links in Taskbar Tabs windows. r=nrishel
This doesn't affect other tab additions, nor does it stop the tab bar
from appearing altogether. The idea is that _if_ another tab is somehow
made, the user should see it; but we should not create new tabs if we
can avoid it.
This also adds tests for opening URIs in popups and taskbar tabs to make
it less likely that this breaks in future.
Differential Revision: https://phabricator.services.mozilla.com/D253726
<!DOCTYPE html><metacharset="utf-8"><title>CSS Values and Units Test: support for the ic unit</title><linkrel="author"title="Kiet Ho"href="mailto:tho22@apple.com"><linkrel="help"href="https://www.w3.org/TR/css-values-4/#ic"><linkrel="match"href="reference/ic-unit-013-ref.html"><metaname="assert"content="The ic unit is equal to 0em if the CJK water glyph's advance is 0."><style>/* The following font contains the CJK water (U+6C34) glyph as a zero-width character. */@font-face{font-family:IcTestZeroWidth;src:url(resources/IcTestZeroWidth.woff2);}.test{font:20pxIcTestZeroWidth;width:calc(100px+10ic);height:20px;background:green;margin-bottom:10px;}.ref{/* Each ic should be equal to 0px because the CJK water glyph in the font is zero-width. */width:100px;height:20px;background:green;}</style><p>The test passes if there are two green rectangles of equal length.</p><divclass="test"></div><divclass="ref"></div>