We should revert bug 1273628 when we have a good solution about bad performances related to CSS var.

Comment on attachment 8791411 [details] Bug 1278177 - Change container icons to a single sprite sheet and to be rendered by CSS https://reviewboard.mozilla.org/r/78822/#review77608 r=me with the following issues fixed and after you have tested with ForceRTL and made sure that what you're doing with the background-position is what you intended. ::: browser/components/contextualidentity/content/usercontext.css:75 (Diff revision 2) > > #userContext-icons { > -moz-box-align: center; > } > + > +tab[usercontextid] { .tabbrowser-tab[usercontextid] ::: browser/components/contextualidentity/content/usercontext.css:82 (Diff revision 2) > + background-size: auto 2px; > + background-repeat: no-repeat; > +} > + > +.menuitem-iconic[data-usercontextid] > .menu-iconic-left > .menu-iconic-icon, > +toolbarbutton[usercontextid] > .toolbarbutton-icon, .toolbarbutton-1[usercontextid] > .toolbarbutton-icon ::: browser/components/contextualidentity/content/usercontext.css:90 (Diff revision 2) > + background-image: var(--identity-icon); > + filter: url(chrome://browser/skin/filters.svg#fill); > + fill: var(--identity-icon-color); > + background-size: contain; > + background-repeat: no-repeat; > + background-position: left center; Have you tested this with the Force-RTL add-on?

Comment on attachment 8791411 [details] Bug 1278177 - Change container icons to a single sprite sheet and to be rendered by CSS https://reviewboard.mozilla.org/r/78822/#review77608 > .toolbarbutton-1[usercontextid] > .toolbarbutton-icon Used .subviewbutton instead of .toolbarbutton-1 as it's for the menus that the container button opens. > Have you tested this with the Force-RTL add-on? Tested with Force-RTL but set the position to be center center anyway which I ended up losing from transfering the patch over to this bug.

Pushed by cbook@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/6f52a805df83 Change container icons to a single sprite sheet and to be rendered by CSS r=jaws

Backed out for failing browser_sessionStoreContainer.js: https://hg.mozilla.org/integration/autoland/rev/e4e51a8149ba5e54054545481f7f9d576880f70d Push following that one has browser-chrome tests which shows the error: https://treeherder.mozilla.org/#/jobs?repo=autoland&revision=8c3384531cc0c11e25f3fd6f3860e00a2fc8e3c7 Failure log: https://treeherder.mozilla.org/logviewer.html#?job_id=6009698&repo=autoland [task 2016-11-02T12:06:29.912658Z] 12:06:29 INFO - Entering test bound [task 2016-11-02T12:06:29.914676Z] 12:06:29 INFO - TEST-PASS | browser/components/sessionstore/test/browser_sessionStoreContainer.js | "1" == 1 - [task 2016-11-02T12:06:29.920986Z] 12:06:29 INFO - TEST-PASS | browser/components/sessionstore/test/browser_sessionStoreContainer.js | The docShell has the correct userContextId - 1 == 1 - [task 2016-11-02T12:06:29.922590Z] 12:06:29 INFO - Leaving test bound [task 2016-11-02T12:06:29.924086Z] 12:06:29 INFO - Entering test bound test [task 2016-11-02T12:06:29.925967Z] 12:06:29 INFO - TEST-UNEXPECTED-FAIL | browser/components/sessionstore/test/browser_sessionStoreContainer.js | Uncaught exception - at resource://gre/modules/ContextualIdentityService.jsm:284 - TypeError: identity is undefined [task 2016-11-02T12:06:29.931857Z] 12:06:29 INFO - Stack trace: [task 2016-11-02T12:06:29.933655Z] 12:06:29 INFO - setTabStyle@resource://gre/modules/ContextualIdentityService.jsm:284:5 [task 2016-11-02T12:06:29.935250Z] 12:06:29 INFO - addTab@chrome://browser/content/tabbrowser.xml:2159:15

also caused failures like https://treeherder.mozilla.org/logviewer.html#?job_id=6014237&repo=autoland

Comment on attachment 8791411 [details] Bug 1278177 - Change container icons to a single sprite sheet and to be rendered by CSS https://reviewboard.mozilla.org/r/78822/#review90172 ::: browser/base/content/browser.js:4133 (Diff revision 3) > hbox.hidden = true; > return; > } > > let identity = ContextualIdentityService.getIdentityFromId(userContextId); > + hbox.setAttribute("data-identity-color", identity.color); there is null check just after this line. You should set the attribute only if identity is not null. ::: toolkit/components/contextualidentity/ContextualIdentityService.jsm:282 (Diff revision 3) > - tab.style.removeProperty("background-repeat"); > return; > } > > let userContextId = tab.getAttribute("usercontextid"); > let identity = this.getIdentityFromId(userContextId); this can return null.

Pushed by amarchesini@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/ab12ade75727 Change container icons to a single sprite sheet and to be rendered by CSS r=jaws