Thanks to Maggie (imjustsomeoneiguess) on discord for helping with a lot of this VP9 media code.
This is the first browser so far to support VP9 Non MFT
* Add javascript.options.weakrefs and plumb it through context options, XPConnect, and workers
* Keep referents alive via strong tracing when the pref is off so deref() still returns the target
* Retain weak-edge semantics when the pref is enabled
Flip the pref. We want this on by default for web compat.
Users can disable it if they really want to, but it doesn't expose
anything of note to web content anyway that can't already be determined.
This DOM/Web API is entirely irrelevant for desktop use.
We give back the width/height of the root scrollframe of content and
for scale we pass forward our dpp resolution (usually 1.0).
Since we have no "no touch" zones in our content on desktop,. the rest
(origin and offset) is hard-coded to (0,0).
See: https://github.com/whatwg/fetch/issues/274#issuecomment-2841053461
Considering the ubiquitous nature of gif, jpg, png, mp4, avi, etc. those
are left out, leaving just jxl, webp, x-matroska (mkv) and webm as
explicitly mentioned supported formats for conneg.
Note: it's not clear where network.http.accept.image is used in practice
because our normal place to use the image override (imgloader) uses
a different pref (image.http.accept).
In the modern era of user-customizable Quick Access sidebars on every file
dialog, navigating via `.lnk` files is considerably less useful than it
was twenty years ago.
Disable link-following in file-open dialogs by default, to prevent any of
the usual security issues involving symlink smuggling.
Allow overriding this behavior via a pref, for users who want to trade off
this security issue for convenience of being able to follow links inside
file dialogs (older OSes and established user workflows).
Note: File Save dialogs have a set of more nuanced guards against link
smuggling and protected file access; this change doesn't affect that.
This is a temporary measure to work around CF OOM situations.
Reporting is desirable normally so webmasters get alerted to CSP issues,
and this should be flipped back on once we can.
