Only allow change-of-basis between transform nodes on the same ancestor chain

cc/trees/property_tree_unittest.cc

Index: cc/trees/property_tree_unittest.cc
diff --git a/cc/trees/property_tree_unittest.cc b/cc/trees/property_tree_unittest.cc
index 8fa13441ba60e50f1e863b5f77e064a37913f6f3..8d15aa3e1f1358bcc3f8ea6d116c338cdd1e4a41 100644
--- a/cc/trees/property_tree_unittest.cc
+++ b/cc/trees/property_tree_unittest.cc
@@ -81,94 +81,6 @@ TEST(PropertyTreeTest, ComputeTransformChild) {
   EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
 }
 
-TEST(PropertyTreeTest, ComputeTransformSibling) {
-  TransformTree tree;
-  TransformNode& root = *tree.Node(0);
-  root.data.local.Translate(2, 2);
-  root.data.target_id = 0;
-  tree.UpdateTransforms(0);
-
-  TransformNode child;
-  child.data.local.Translate(3, 3);
-  child.data.target_id = 0;
-
-  TransformNode sibling;
-  sibling.data.local.Translate(7, 7);
-  sibling.data.target_id = 0;
-
-  tree.Insert(child, 0);
-  tree.Insert(sibling, 0);
-
-  tree.UpdateTransforms(1);
-  tree.UpdateTransforms(2);
-
-  gfx::Transform expected;
-  gfx::Transform transform;
-
-  expected.Translate(4, 4);
-  bool success = tree.ComputeTransform(2, 1, &transform);
-  EXPECT_TRUE(success);
-  EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
-
-  transform.MakeIdentity();
-  expected.MakeIdentity();
-  expected.Translate(-4, -4);
-  success = tree.ComputeTransform(1, 2, &transform);
-  EXPECT_TRUE(success);
-  EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
-}
-
-TEST(PropertyTreeTest, ComputeTransformSiblingSingularAncestor) {
-  // In this test, we have the following tree:
-  // root
-  //   + singular
-  //     + child
-  //     + sibling
-  // Now singular has a singular transform, so we cannot use screen space
-  // transforms to compute change of basis transforms between |child| and
-  // |sibling|.
-  TransformTree tree;
-  TransformNode& root = *tree.Node(0);
-  root.data.local.Translate(2, 2);
-  root.data.target_id = 0;
-  tree.UpdateTransforms(0);
-
-  TransformNode singular;
-  singular.data.local.matrix().set(2, 2, 0.0);
-  singular.data.target_id = 0;
-
-  TransformNode child;
-  child.data.local.Translate(3, 3);
-  child.data.target_id = 0;
-
-  TransformNode sibling;
-  sibling.data.local.Translate(7, 7);
-  sibling.data.target_id = 0;
-
-  tree.Insert(singular, 0);
-  tree.Insert(child, 1);
-  tree.Insert(sibling, 1);
-
-  tree.UpdateTransforms(1);
-  tree.UpdateTransforms(2);
-  tree.UpdateTransforms(3);
-
-  gfx::Transform expected;
-  gfx::Transform transform;
-
-  expected.Translate(4, 4);
-  bool success = tree.ComputeTransform(3, 2, &transform);
-  EXPECT_TRUE(success);
-  EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
-
-  transform.MakeIdentity();
-  expected.MakeIdentity();
-  expected.Translate(-4, -4);
-  success = tree.ComputeTransform(2, 3, &transform);
-  EXPECT_TRUE(success);
-  EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
-}
-
 TEST(PropertyTreeTest, TransformsWithFlattening) {
   TransformTree tree;