959953 - JavaScript Warning: "Unknown property 'will-change'. Declaration dropped." {file: "app://settings.gaiamobile.org/style/settings.css"

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Gaia::Settings, defect)

Description

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

+++ This bug was initially created as a clone of Bug #959936 +++

E/GeckoConsole(  529): [JavaScript Warning: "Unknown property 'will-change'.  Declaration dropped." {file: "app://settings.gaiamobile.org/style/settings.css" line: 71 column: 13 source: "  will-change: scroll-position;"}]

This happens after starting up the emulator, tested with the jb version of the emulator in pvt builds, with timestamp 20140114154437, then launching the Settings app.

https://github.com/mozilla-b2g/gaia/blame/4cc2dcbf9cebf6d4731783626acf57c3e712f479/apps/settings/style/settings.css#L71

This line was changed in:

https://github.com/mozilla-b2g/gaia/commit/c6ab2ccd2bd7ee5ffb604a051db890a729f5aa13

via bug 950498, so setting needinfo? from Mason.

Comment 1

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

FWIW, launching the Contacts app will also result in:

E/GeckoConsole(  642): [JavaScript Warning: "Unknown property 'will-change'.  Declaration dropped." {file: "app://communications.gaiamobile.org/contacts/style/app.css" line: 349 column: 13 source: "  will-change: scroll-position;"}]
E/GeckoConsole(  642): [JavaScript Warning: "Unknown property 'will-change'.  Declaration dropped." {file: "app://communications.gaiamobile.org/contacts/style/contacts.css" line: 41 column: 13 source: "  will-change: scroll-position;"}]

For now, I'm assuming they're related, because the following commit:

https://github.com/mozilla-b2g/gaia/blame/4cc2dcbf9cebf6d4731783626acf57c3e712f479/apps/communications/contacts/style/app.css#L349

seems to also point to bug 950498.

Comment 2

[Mason Chang [Inactive] [:mchang]]

Yes, we're still waiting on bug 940842 to land, which will enable support for this in Gecko. This is expected behavior until it lands properly in Gecko.

Comment 3

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

I no longer see JavaScript warnings when launching the Settings app.

Tested with the Flame on:

$ ./check_versions.sh
Gaia      0f9f11d0a6dadb3ea27160204bbe911c1ad69a6f
Gecko     https://hg.mozilla.org/mozilla-central/rev/196d05832e12
BuildID   20140709040203
Version   33.0a1
ro.build.version.incremental=109
ro.build.date=Mon Jun 16 16:51:29 CST 2014
B1TC00011220

Assuming fixed by bug 940842 which landed for Gecko 29, i.e. FxOS 1.4 and later should have this fix.