In the SVG test case mentioned in the URL on nightly the masked skyblue area is not showing at all. At first I thought this was Azure content but it turns out to be broken everywhere (with/without Azure content and with/without Direct2D). One odd thing I noticed is that userData->mXScale and userData->mYScale were 6.6... inside FrameLayerBuilder. I wonder if this has to do with DLBI.

The mask appears if I disable SVG display lists. It still doesn't appear to be rendered correctly though.

There are 2 regressions. #1 The outside rectangle is filled up with skyblue, too: Regressed by Bug 715768 #2 Nothing is filled with skyblue: Regressed by Bug 776054 #1Regression window(m-c) Good: http://hg.mozilla.org/mozilla-central/rev/36e938e51481 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/15.0 Firefox/15.0a1 ID:20120523030525 Bad: http://hg.mozilla.org/mozilla-central/rev/aa2b52bd0374 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/15.0 Firefox/15.0a1 ID:20120523024422 Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=36e938e51481&tochange=aa2b52bd0374 #1Regression window(m-i) Good: http://hg.mozilla.org/integration/mozilla-inbound/rev/bbb12d0bcf49 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/15.0 Firefox/15.0a1 ID:20120521220651 Bad: http://hg.mozilla.org/integration/mozilla-inbound/rev/abbf642df562 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/15.0 Firefox/15.0a1 ID:20120521222950 Pushlog: http://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=bbb12d0bcf49&tochange=abbf642df562 #1Suspected: Bug 715768 #2Regression window(m-c) Good: http://hg.mozilla.org/mozilla-central/rev/688734575830 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120802041638 Bad: http://hg.mozilla.org/mozilla-central/rev/074fb996dfd7 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120802062038 Pushlog http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=688734575830&tochange=074fb996dfd7 #2Regression window(m-i) Good: http://hg.mozilla.org/integration/mozilla-inbound/rev/a799b5bff84c Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120801155239 Bad: http://hg.mozilla.org/integration/mozilla-inbound/rev/b077c43a4306 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120801163038 Pushlog http://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=a799b5bff84c&tochange=b077c43a4306 #2Suspected: Bug 776054

Seems to work now.

I can confirm the patch for bug 806432 fixed this.

Verified fixed FF 19b4 Win 7, Ubuntu 12.04 and Mac OS X 10.7.5