Update from https://crrev.com/320343

cc/resources/layer_quad.h

Index: cc/resources/layer_quad.h
diff --git a/cc/resources/layer_quad.h b/cc/resources/layer_quad.h
index ed1db101a9737119fe14799931335a5c686768c0..74336453683f4c94dffc589e5e5145e07c455180 100644
--- a/cc/resources/layer_quad.h
+++ b/cc/resources/layer_quad.h
@@ -22,7 +22,7 @@ class CC_EXPORT LayerQuad {
  public:
   class Edge {
    public:
-    Edge() : x_(0), y_(0), z_(0) {}
+    Edge() : x_(0), y_(0), z_(0), degenerate_(false) {}
     Edge(const gfx::PointF& p, const gfx::PointF& q);
 
     float x() const { return x_; }
@@ -57,6 +57,8 @@ class CC_EXPORT LayerQuad {
     }
     void scale(float s) { scale(s, s, s); }
 
+    bool degenerate() const { return degenerate_; }
+
     gfx::PointF Intersect(const Edge& e) const {
       return gfx::PointF(
           (y() * e.z() - e.y() * z()) / (x() * e.y() - e.x() * y()),
@@ -67,6 +69,7 @@ class CC_EXPORT LayerQuad {
     float x_;
     float y_;
     float z_;
+    bool degenerate_;
   };
 
   LayerQuad(const Edge& left,