This prevents TextDrawTarget from needing to do any unnecessary allocations/copies (other than the class itself). It also significantly simplifies our code. Possible downside: moves us further away from retaining textFrame layout results? Not necessarily important if we can just make everything fast enough. I have a patch ready, just need some webrender updates to land.

Patch up for perf evaluation.

Comment on attachment 8917222 [details] Bug 1406510 - rewrite TextDrawTarget to push directly into display list. https://reviewboard.mozilla.org/r/188242/#review193764 Looks good to me. As discussed, let's wait for text layers to be turned on before landing this so we get testing.

Kicked off a try build https://treeherder.mozilla.org/#/jobs?repo=try&revision=69a3cac0e72ec6bb4140fe87f263b8a1a911b27b

Pushed by ryanvm@gmail.com: https://hg.mozilla.org/integration/autoland/rev/2ab5ef946a40 rewrite TextDrawTarget to push directly into display list. r=jrmuizel

Backout by ryanvm@gmail.com: https://hg.mozilla.org/integration/autoland/rev/2eaa3fcaf6db Backed out changeset 2ab5ef946a40 for test failures.

Missing TerminateShadows call, good to go.

Pushed by jmuizelaar@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/722270790476 rewrite TextDrawTarget to push directly into display list. r=jrmuizel

Pushed by ryanvm@gmail.com: https://hg.mozilla.org/integration/autoland/rev/c1f9baaa7b63 rewrite TextDrawTarget to push directly into display list. r=jrmuizel

Backout by ryanvm@gmail.com: https://hg.mozilla.org/integration/autoland/rev/2b746fdf27e0 Backed out changeset c1f9baaa7b63 because it was already landed on inbound while autoland was closed.