[LayoutNG] Don't implement ContainerSize() using the physical constraint space.

third_party/WebKit/Source/core/layout/ng/ng_constraint_space_test.cc

Index: third_party/WebKit/Source/core/layout/ng/ng_constraint_space_test.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_test.cc b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_test.cc
index 6daea5c8b16cda8bac7df7ed3aceeda039fb119e..bc4ad51cfcae944ec2a3e0fabbd311e954e8bf65 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_test.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_test.cc
@@ -88,6 +88,21 @@ TEST(NGConstraintSpaceTest, LayoutOpportunitiesOneExclusion) {
   EXPECT_EQ(nullptr, secondOpportunity);
 }
 
+TEST(NGConstraintSpaceTest, ContainerSize) {
+  NGPhysicalSize physical_size;
+  physical_size.width = LayoutUnit(800);
+  physical_size.height = LayoutUnit(600);
+  auto* physical_space = new NGPhysicalConstraintSpace(physical_size);
+
+  auto* space = new NGConstraintSpace(HorizontalTopBottom, physical_space);
+  auto* derived_space =
+      new NGConstraintSpace(*space, NGLogicalOffset(),
+                            NGLogicalSize(LayoutUnit(200), LayoutUnit(300)));
+
+  EXPECT_EQ(LayoutUnit(200), derived_space->ContainerSize().inline_size);
+  EXPECT_EQ(LayoutUnit(300), derived_space->ContainerSize().block_size);
+}
+
 }  // namespace
 
 }  // namespace blink