Chromium -> Mojo roll.

cc/resources/layer_quad_unittest.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/resources/layer_quad.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/geometry/quad_f.h"
 
 namespace cc {
@@ skipping 20 matching lines @@
   gfx::PointF p3(0.5f, 0.5f);
   gfx::PointF p4(-0.5f, 0.5f);
 
   gfx::QuadF quad(p1, p2, p3, p4);
   LayerQuad layer_quad(quad);
   quad.Scale(2.f, 2.f);
   layer_quad.Inflate(0.5f);
   EXPECT_EQ(layer_quad.ToQuadF(), quad);
 }
 
+TEST(LayerQuadTest, Degenerate) {
+  gfx::QuadF quad;
+  gfx::PointF p1(1.0f, 1.0f);
+  gfx::PointF p2(0.0f, 1.0f);
+  gfx::PointF p3(1.0f, 0.0f);
+  gfx::QuadF triangle(p1, p2, p3, p1);
+
+  LayerQuad::Edge e1d(p1, p1);
+  LayerQuad::Edge e2d(p2, p2);
+  LayerQuad::Edge e2(p1, p2);
+  LayerQuad::Edge e3(p2, p3);
+  LayerQuad::Edge e4(p3, p1);
+  EXPECT_TRUE(e1d.degenerate());
+  EXPECT_TRUE(e2d.degenerate());
+  EXPECT_FALSE(e2.degenerate());
+  EXPECT_FALSE(e3.degenerate());
+  EXPECT_FALSE(e4.degenerate());
+
+  LayerQuad degenerate_quad(e1d, e2d, e2, e3);
+  // With more than one degenerate edge, we expect the quad to be zero.
+  EXPECT_EQ(quad, degenerate_quad.ToQuadF());
+
+  LayerQuad triangle_quad(e1d, e2, e3, e4);
+  // With only one degenerate edge, we expect the quad to be a triangle.
+  EXPECT_EQ(triangle, triangle_quad.ToQuadF());
+}
+
 }  // namespace
 }  // namespace cc