1316718 - Remove ExtensionContent from mozbrowser startup

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect, P1)

Description

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

We currently try to init ExtensionContent for any mozbrowser frame, but this seems like it is a B2G-specific detail.

Outside of B2G, we don't need to do this today because we already load ExtensionContent as needed at other points in the code base.

Since we're removing B2G specifics, it seems logical to remove this at this stage.

Comment 1

[Kris Maglione [:kmag]]

I think this is actually still necessary if we want WebExtension content scripts to run in mozbrowser children.

Comment 2

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

(In reply to Kris Maglione [:kmag] from comment #1)
> I think this is actually still necessary if we want WebExtension content
> scripts to run in mozbrowser children.

Yes, it's necessary for _someone_ to init ExtensionContent for the content globals that run in a frame if we want content scripts to apply there.  I am just not convinced that we need to "intertwine" that with "starting the mozbrowser API" like we do today for mozbrowser frames.  It seems like it was just a convenient place to put it for the B2G case.

AFAIK, the only usage of mozbrowser on desktop at the moment is the DevTools Responsive Design Mode I am working on.  In my case, it's unnecessary to start ExtensionContent in the current mozbrowser way because I am swapping content from a <xul:browser> into <iframe mozbrowser>, so ExtensionContent has already been inited by browser/base/content/tab-content.js.

If we start creating fresh mozbrowser frames from nothing on desktop, I imagine we'd create a place to start ExtensionContent for them, but that's not something we seem to use yet.

Is there some other case that you'd like to keep things as is for?

Comment 3

[Kris Maglione [:kmag]]

I guess at this point it probably doesn't matter much. I'm mainly just worried that as we start using mozbrowser more (for instance, from extensions that want to display web content), we're going to wind up missing things that should be expected to work.

Comment 4

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

Attachment: Bug 1316718 - Remove ExtensionContent from mozbrowser startup.

Review commit: https://reviewboard.mozilla.org/r/92156/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/92156/

Comment 5

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=8681e730cd245ada1aec2394291bcf480a0a42fa

Comment 6

[[:fabrice] Fabrice Desré]

Comment on attachment 8809611 [details]
Bug 1316718 - Remove ExtensionContent from mozbrowser startup.

https://reviewboard.mozilla.org/r/92156/#review93300

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/6c48b4a38d70
Remove ExtensionContent from mozbrowser startup. r=fabrice

Comment 8

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/6c48b4a38d70