Reland "GrTessellator: hang fix."

This is a reland of 050c86768a2c24c62655f53ef9b685d40477eccb

Original change's description:
> GrTessellator: hang fix.
> 
> Some edges are not coincident with their own endpoints (because floating
> point). If this happens for an edge which is a right-enclosing-edge
> during the Bentley-Ottman simplify() pass, we end up an infinite loop
> attempting to split the edge, since the edge is never to the right of its
> endpoint.
> 
> The easiest fix is to simply remove the right-enclosing-edge splitting
> code. This code was originally added before we had proper
> active-edge-list rewinding, and should no longer be necessary.
> 
> BUG=802896
> 
> Change-Id: Id9f2942b73f01152af8c0088e8c6b1389891d827
> Reviewed-on: https://skia-review.googlesource.com/116920
> Reviewed-by: Robert Phillips <robertphillips@google.com>
> Commit-Queue: Stephen White <senorblanco@chromium.org>

Bug: 802896
Change-Id: I3e48346a8a358ae7d481299a586003e817a519ca
Reviewed-on: https://skia-review.googlesource.com/117121
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>

1 files changed, 0 insertions, 6 deletions

diff --git a/src/gpu/GrTessellator.cpp b/src/gpu/GrTessellator.cpp
index 00e5c8a21c..b8ec6551c9 100644
--- a/src/gpu/GrTessellator.cpp
+++ b/src/gpu/GrTessellator.cpp
@@ -1421,12 +1421,6 @@ bool simplify(VertexList* mesh, Comparator& c, SkArenaAlloc& alloc) {
             LOG("\nvertex %g: (%g,%g), alpha %d\n", v->fID, v->fPoint.fX, v->fPoint.fY, v->fAlpha);
             restartChecks = false;
             find_enclosing_edges(v, &activeEdges, &leftEnclosingEdge, &rightEnclosingEdge);
-            if (rightEnclosingEdge && !rightEnclosingEdge->isRightOf(v)) {
-                split_edge(rightEnclosingEdge, v, &activeEdges, &v, c, alloc);
-                restartChecks = true;
-                continue;
-            }
-            SkASSERT(!rightEnclosingEdge || rightEnclosingEdge->isRightOf(v));
             v->fLeftEnclosingEdge = leftEnclosingEdge;
             v->fRightEnclosingEdge = rightEnclosingEdge;
             if (v->fFirstEdgeBelow) {