This patch makes several changes to the kinds of URLs where we can cancel
content JS when navigating between them:
1) When navigating directly to a URL (e.g. by typing something into the
location bar and hitting Enter), we allow canceling content JS if the URLs
differ in any way *except* their ref ("#"). To help with this, we also
attempt to fix up the URL (e.g. by prepending "http://" to it).
2) When navigating through history, we allow canceling content JS if the
`prePath` part of the URLs differ. Most notably, this allows canceling
content JS when one of the URLs is an `about:` page (e.g. when hitting the
Home button).
3) We explicitly disallow cancelling content JS if the currently-running JS
is trusted or if the page being navigated away from is anything but
http(s): or file:.
4) We also disallow cancelling content JS for windows that are still being
created (e.g. when creating a new tab or window via `window.open`). For
more background on this, see the comments about `mCreatingWindow` in
dom/ipc/BrowserParent.h.
5) We ensure that, when attempting to cancel JS, the tab ID of the
currently-running script matches the original tab that requested the
cancellation. This avoids a race condition in which a particular JSContext
has already moved on to executing another tab's JS by the time we hit our
interrupt callback.
Differential Revision: https://phabricator.services.mozilla.com/D31875
--HG--
extra : moz-landing-system : lando
Also taking the opportunity to rework the nsIURIFixupInfo interface to use more sensible booleans, and the relevant test to specify outcomes directly, instead of trying to use the same logic as the implementation to infer them from the input.
--HG--
extra : rebase_source : 43b54b9ff412c05dc3fd2575a80919fc085d2d49
