This heuristic makes more sense than the previous "ifs with a
discontinuous loop" as the reason we need to flatten is that we need
gradients to be in branchless code.
Change the UnrollFlatten test accordingly.
Tested with:
- the WebGL CTS
- dev.miaumiau.cat/rayTracer "Skull Demo"
- THe turbulenz engine GPU particle demo
- Lots of ShaderToy Samples (inc. Volcanic, Metropolis and Hierarchical
Voronoi)
- Google Maps Earth mode
- Lots of Chrome experiments
- madebyevan.com/webgl-water
BUG=524297
Change-Id: Iaa727036fffcfde3952716a1ef33b6ee0546b69d
Reviewed-on: https://chromium-review.googlesource.com/296442Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Corentin Wallez <cwallez@chromium.org>
