Account for perspective and preserve-3d in mapToVisualRectInAncestorSpace

third_party/WebKit/Source/core/layout/VisualRectMappingTest.cpp

Index: third_party/WebKit/Source/core/layout/VisualRectMappingTest.cpp
diff --git a/third_party/WebKit/Source/core/layout/VisualRectMappingTest.cpp b/third_party/WebKit/Source/core/layout/VisualRectMappingTest.cpp
index af9aa37f8a27a0a6f34c160f1fe73449611d5583..4020dfa38809c7f7df9ce382a976a86b22a6754d 100644
--- a/third_party/WebKit/Source/core/layout/VisualRectMappingTest.cpp
+++ b/third_party/WebKit/Source/core/layout/VisualRectMappingTest.cpp
@@ -700,4 +700,69 @@ TEST_F(VisualRectMappingTest, FloatUnderInline) {
   EXPECT_EQ(LayoutRect(-200, -100, 33, 44), rect);
 }
 
+TEST_F(VisualRectMappingTest, ShouldAccountForPreserve3d) {
+  enableCompositing();
+  setBodyInnerHTML(
+      "<style>"
+      "* { margin: 0; }"
+      "#container {"
+      "  transform: rotateX(-45deg);"
+      "  width: 100px; height: 100px;"
+      "}"
+      "#target {"
+      "  transform-style: preserve-3d; transform: rotateX(45deg);"
+      "  background: lightblue;"
+      "  width: 100px; height: 100px;"
+      "}"
+      "</style>"
+      "<div id='container'><div id='target'></div></div>");
+  LayoutBlock* container =
+      toLayoutBlock(getLayoutObjectByElementId("container"));
+  LayoutBlock* target = toLayoutBlock(getLayoutObjectByElementId("target"));
+  LayoutRect originalRect(0, 0, 100, 100);
+  // Multiply both matrices together before flattening.
+  TransformationMatrix matrix = container->layer()->currentTransform();
+  matrix *= target->layer()->currentTransform();
+  matrix.flattenTo2d();
+  FloatRect output = matrix.mapRect(FloatRect(originalRect));
+
+  EXPECT_TRUE(
+      target->mapToVisualRectInAncestorSpace(target->view(), originalRect));
+  EXPECT_EQ(LayoutRect(enclosingIntRect(output)), originalRect);
+}
+
+TEST_F(VisualRectMappingTest, ShouldAccountForPerspective) {
+  enableCompositing();
+  setBodyInnerHTML(
+      "<style>"
+      "* { margin: 0; }"
+      "#container {"
+      "  transform: rotateX(-45deg); perspective: 100px;"
+      "  width: 100px; height: 100px;"
+      "}"
+      "#target {"
+      "  transform-style: preserve-3d; transform: rotateX(45deg);"
+      "  background: lightblue;"
+      "  width: 100px; height: 100px;"
+      "}"
+      "</style>"
+      "<div id='container'><div id='target'></div></div>");
+  LayoutBlock* container =
+      toLayoutBlock(getLayoutObjectByElementId("container"));
+  LayoutBlock* target = toLayoutBlock(getLayoutObjectByElementId("target"));
+  LayoutRect originalRect(0, 0, 100, 100);
+  TransformationMatrix matrix = container->layer()->currentTransform();
+  TransformationMatrix targetMatrix;
+  // getTransformfromContainter includes transform and perspective matrix
+  // of the container.
+  target->getTransformFromContainer(container, LayoutSize(), targetMatrix);
+  matrix *= targetMatrix;
+  matrix.flattenTo2d();
+  FloatRect output = matrix.mapRect(FloatRect(originalRect));
+
+  EXPECT_TRUE(
+      target->mapToVisualRectInAncestorSpace(target->view(), originalRect));
+  EXPECT_EQ(LayoutRect(enclosingIntRect(output)), originalRect);
+}
+
 }  // namespace blink