Avoid duplicate math when computing VR scene hierarchy.

chrome/browser/android/vr_shell/ui_scene_unittest.cc

Index: chrome/browser/android/vr_shell/ui_scene_unittest.cc
diff --git a/chrome/browser/android/vr_shell/ui_scene_unittest.cc b/chrome/browser/android/vr_shell/ui_scene_unittest.cc
index c58f94b616f70d341b4521fad66d0012d36fa396..a538189806f07ea3550242f6b385602ca9d866a4 100644
--- a/chrome/browser/android/vr_shell/ui_scene_unittest.cc
+++ b/chrome/browser/android/vr_shell/ui_scene_unittest.cc
@@ -126,7 +126,6 @@ TEST(UiScene, ParentTransformAppliesToChild) {
   const gvr::Vec3f origin({0, 0, 0});
   const gvr::Vec3f point({1, 0, 0});
 
-  // Check resulting transform with no screen tilt.
   scene.UpdateTransforms(0);
   auto new_origin = MatrixVectorMul(child->TransformMatrix(), origin);
   auto new_point = MatrixVectorMul(child->TransformMatrix(), point);