1358524 - stylo: User sheets are not loaded in e10s mode for content pages

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect, P2)

Description

[Fernando Jiménez Moreno [:ferjm]]

User sheets are not applied to content pages in e10s mode.

For example, if I add this chrome/userContent.css content to my profile:

body {
  background: lime !important;
}

Running a stylo enabled firefox with "./mach run" shows about:home and https://google.com with no modifications.

Running a stylo enabled firefox with "./mach run --disable-e10s" shows about:home and https://google.com with a lime background as expected.

For chrome pages like about:newtab, user styles are always applied.

Comment 1

[Bobby Holley (:bholley)]

Over to Fernando for investigation.

Comment 2

[Masatoshi Kimura [:emk]]

nsDocumentViewer will take a UserContentSheet based on the backend type[1], but only one backend can initialize mUserContentSheet in content processes[2]. So user stylesheets will work only in one backend (currently, it happens to be the Gecko backend.)

[1] https://dxr.mozilla.org/mozilla-central/rev/a748acbebbde373a88868dc02910fb2bc5e6a023/layout/base/nsDocumentViewer.cpp#2295,2302
[2] https://dxr.mozilla.org/mozilla-central/rev/a748acbebbde373a88868dc02910fb2bc5e6a023/layout/style/nsLayoutStylesheetCache.cpp#354-358

Comment 3

[Masatoshi Kimura [:emk]]

Attachment: Bug 1358524 - Load userContent.css on both style backends in e10s.

Review commit: https://reviewboard.mozilla.org/r/135944/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/135944/

Comment 4

[Masatoshi Kimura [:emk]]

usercss.html passed with this patch and patches from bug 1355408.
https://treeherder.mozilla.org/#/jobs?repo=try&revision=2404182b964e602641a615180f26eb9f39a73e55

Comment 5

[Fernando Jiménez Moreno [:ferjm]]

Thank you Masatoshi! Since you already provided a patch I'm assigning you the issue.

Comment 6

[Masatoshi Kimura [:emk]]

Comment on attachment 8864314 [details]
Bug 1358524 - Load userContent.css on both style backends in e10s.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/135944/diff/1-2/

Comment 7

[Masatoshi Kimura [:emk]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=68fa4f38a2b3b9dd7089638819ccc37a17e643a2

Comment 8

[Bobby Holley (:bholley)]

Comment on attachment 8864314 [details]
Bug 1358524 - Load userContent.css on both style backends in e10s.

https://reviewboard.mozilla.org/r/135944/#review139318

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/dcc5b9d4c114
Load userContent.css on both style backends in e10s. r=bholley

Comment 10

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/dcc5b9d4c114