Fix SkASSERT for convex paths with DAA

As DAA does not chop edges at Y extrema, it's valid for convex edges to
have only one edge (e.g., a single cubic edge with the valley shape \_/).

This wasn't an issue for production because DAA is never called for
convex paths by default.

Bug=skia:7015
Change-Id: Iac79801d6a24188970ef6f7bf723494a25d92a1e
Reviewed-on: https://skia-review.googlesource.com/42942
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Yuqian Li <liyuqian@google.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/dm/DM.cpp b/dm/DM.cpp
index 044fea5907..7954744c90 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -1320,6 +1320,9 @@ int main(int argc, char** argv) {
     if (FLAGS_forceAnalyticAA) {
         gSkForceAnalyticAA = true;
     }
+    if (FLAGS_forceDeltaAA) {
+        gSkForceDeltaAA = true;
+    }
     if (FLAGS_forceRasterPipeline) {
         gSkForceRasterPipelineBlitter = true;
     }