971124 - Use an ::after element to workaround for backgound-attachment: fixed making start page watermark jittery

Status: VERIFIED FIXED

(Firefox for Metro Graveyard :: Firefox Start, defect, P1)

Description

[Rodrigo Silveira [:rsilveira] [:rodms]]

Attachment: Patch v1

Using a fixed ::after element for watermark. Doesn't jitter but seems to affect scroll perf on my machine.

Comment 1

[Jim Mathies [:jimm]]

I ran a mochiperf test I wrote that measures about:start frame rates on my surface pro. We gain a little by not having the watermark at all, but your fix doesn't appear to be any different from the old way we did things. I say we land this.

frame rates - lowest, average, highest

without:
12.78128948211673, 18.59786614073508, 36.36217947006226
12.63769250167044, 18.62844010021375, 35.69318911903783
13.99339901773557, 18.51968537923452, 35.94249534606933

with:
12.57155618667602, 20.24701798523908, 41.5103327751159
11.65082846189800, 20.54952812194824, 46.2052700645045
13.53932342529296, 19.32422757747784, 38.7889627456665

old watermark:
12.74443211555481, 20.20959343659250, 44.13960485458374
13.13732051849365, 19.86325096827681, 43.41022511532432
12.20469630391974, 20.44748240805961, 46.02304097225792

http://mxr.mozilla.org/mozilla-central/source/browser/metro/base/tests/mochiperf/browser_apzc.js#175
http://www.mathies.com/mozilla/mochiperf.html?testid=2E60F8B5-8925-4628-988E-E4C0BC6B34C7

Comment 2

[Rodrigo Silveira [:rsilveira] [:rodms]]

Attachment: Patch v2

using negative margin instead of calc.

Comment 3

[Rodrigo Silveira [:rsilveira] [:rodms]]

https://hg.mozilla.org/integration/fx-team/rev/2c154d398ab2

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/2c154d398ab2

Comment 5

[Jim Mathies [:jimm]]

Are we going to uplift this to beta?

Comment 6

[Rodrigo Silveira [:rsilveira] [:rodms]]

(In reply to Jim Mathies [:jimm] from comment #5)
> Are we going to uplift this to beta?

We don't have a fix for bug 969356 yet, that's why I'm holding this one.

Comment 7

[Rodrigo Silveira [:rsilveira] [:rodms]]

Now that bug 969356 has landed and is verified we can uplift this one. Juan, can you verify it?

Comment 8

[Kamil Jozwiak [:kjozwiak]]

Went through the following verification process using the following build:
- http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2014-02-24-03-02-03-mozilla-central/

Used the following test cases

- Scrolled through the about:start screen window right after an installation
- Added several website tiles into the "Top Sites" category and scrolled through about:start
- Added several website tiles into the "Bookmarks" category and scrolled through about:start
- Ensured that there was enough website tiles under "Recent History" and scrolled through about:start
- Scrolled through the about:start using several methods (scroll bars, mouse wheel, keyboard arrows, touch)
- Went through all of the above test cases using several variations of snapped view
- Went through the following test cases using both the X1 Carbon and the Surface Pro 2

I did find Bug #976278 when going through this issue. Marking this as verified as the original issue has been fixed.

Comment 9

[Rodrigo Silveira [:rsilveira] [:rodms]]

Comment on attachment 8374624 [details] [diff] [review]
Patch v2

[Approval Request Comment]
Bug caused by (feature/regressing bug #): This is a workaround for bug 970942.
User impact if declined: No watermark will be displayed in metro's start page. It's the most visible piece of branding we have on start page
Testing completed (on m-c, etc.): On m-c since 02/13. Also QA tested, see comment #8
Risk to taking this patch (and alternatives if risky): Very low, css change that affects metro only. Note that bug 969356 also impacts the watermark and would be better if both could be uplifted.
String or IDL/UUID changes made by this patch: none

Comment 10

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/e245c793a38e

Comment 11

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/00c79b181299

Comment 12

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-b2g28_v1_3/rev/00c79b181299

Comment 13

[Kamil Jozwiak [:kjozwiak]]

Changing this back to resolved, will need to verify Aurora/BETA. Marking Nightly as verified as per comment #8

Comment 14

[Kamil Jozwiak [:kjozwiak]]

Went through the following verification process using the following build:
- http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2014-02-26-00-40-01-mozilla-aurora/

- Went through the original test cases from comment #0
- Went through all the test cases from comment #8

Patch didn't make it into Firefox 28.0b6, waiting for a newer BETA to complete verification.

Comment 15

[Kamil Jozwiak [:kjozwiak]]

Went through the following verification process using the following build:
- http://ftp.mozilla.org/pub/mozilla.org/firefox/releases/28.0b7/win32/en-US/

- Went through the original test case from comment #0
- Went through all of the test cases from comment #8
- Went through the above test cases using both the X1 Carbon and the Surface Pro 2