[LayoutNG] Switch NGConstraintSpace to being RefCounted.

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

 // Copyright 2016 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 "core/layout/ng/ng_block_layout_algorithm.h"
 
 #include "core/dom/NodeComputedStyle.h"
 #include "core/dom/TagCollection.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "core/layout/ng/layout_ng_block_flow.h"
 #include "core/layout/ng/ng_block_break_token.h"
 #include "core/layout/ng/ng_block_node.h"
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_constraint_space_builder.h"
 #include "core/layout/ng/ng_floating_object.h"
 #include "core/layout/ng/ng_length_utils.h"
 #include "core/layout/ng/ng_physical_box_fragment.h"
 #include "core/layout/ng/ng_physical_fragment.h"
 #include "core/layout/ng/ng_units.h"
 #include "core/style/ComputedStyle.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace blink {
 namespace {
 
 using testing::ElementsAre;
 using testing::Pointee;
 
-NGConstraintSpace* ConstructConstraintSpace(
+RefPtr<NGConstraintSpace> ConstructConstraintSpace(
     NGWritingMode writing_mode,
     TextDirection direction,
     NGLogicalSize size,
     bool shrink_to_fit = false,
     LayoutUnit fragmentainer_space_available = LayoutUnit()) {
   NGFragmentationType block_fragmentation =
       fragmentainer_space_available != LayoutUnit()
           ? NGFragmentationType::kFragmentColumn
           : NGFragmentationType::kFragmentNone;
 
@@ skipping 31 matching lines @@
 
   RefPtr<NGPhysicalBoxFragment> RunBlockLayoutAlgorithm(
       NGConstraintSpace* space,
       NGBlockNode* node) {
     RefPtr<NGLayoutResult> result =
         NGBlockLayoutAlgorithm(node, space).Layout();
 
     return toNGPhysicalBoxFragment(result->PhysicalFragment().get());
   }
 
-  std::pair<RefPtr<NGPhysicalBoxFragment>, NGConstraintSpace*>
+  std::pair<RefPtr<NGPhysicalBoxFragment>, RefPtr<NGConstraintSpace>>
   RunBlockLayoutAlgorithmForElement(Element* element) {
     LayoutNGBlockFlow* block_flow =
         toLayoutNGBlockFlow(element->layoutObject());
     NGBlockNode* node = new NGBlockNode(block_flow);
-    NGConstraintSpace* space =
+    RefPtr<NGConstraintSpace> space =
         NGConstraintSpace::CreateFromLayoutObject(*block_flow);
 
     RefPtr<NGLayoutResult> result =
-        NGBlockLayoutAlgorithm(node, space).Layout();
+        NGBlockLayoutAlgorithm(node, space.get()).Layout();
     return std::make_pair(
         toNGPhysicalBoxFragment(result->PhysicalFragment().get()), space);
   }
 
   MinAndMaxContentSizes RunComputeMinAndMax(NGBlockNode* node) {
     // The constraint space is not used for min/max computation, but we need
     // it to create the algorithm.
-    NGConstraintSpace* space =
+    RefPtr<NGConstraintSpace> space =
         ConstructConstraintSpace(kHorizontalTopBottom, TextDirection::kLtr,
                                  NGLogicalSize(LayoutUnit(), LayoutUnit()));
 
-    NGBlockLayoutAlgorithm algorithm(node, space);
+    NGBlockLayoutAlgorithm algorithm(node, space.get());
     EXPECT_TRUE(algorithm.ComputeMinAndMaxContentSizes().has_value());
     return *algorithm.ComputeMinAndMaxContentSizes();
   }
 
   RefPtr<ComputedStyle> style_;
 };
 
 TEST_F(NGBlockLayoutAlgorithmTest, FixedSize) {
   setBodyInnerHTML(R"HTML(
     <div id="box" style="width:30px; height:40px"></div>
   )HTML");
 
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(100), NGSizeIndefinite));
 
   auto* box = new NGBlockNode(getLayoutObjectByElementId("box"));
 
-  RefPtr<NGPhysicalFragment> frag = RunBlockLayoutAlgorithm(space, box);
+  RefPtr<NGPhysicalFragment> frag = RunBlockLayoutAlgorithm(space.get(), box);
 
   EXPECT_EQ(LayoutUnit(30), frag->Width());
   EXPECT_EQ(LayoutUnit(40), frag->Height());
 }
 
 // Verifies that two children are laid out with the correct size and position.
 TEST_F(NGBlockLayoutAlgorithmTest, LayoutBlockChildren) {
   setBodyInnerHTML(R"HTML(
     <div id="container" style="width: 30px">
       <div style="height: 20px">
       </div>
       <div style="height: 30px; margin-top: 5px; margin-bottom: 20px">
       </div>
     </div>
   )HTML");
   const int kWidth = 30;
   const int kHeight1 = 20;
   const int kHeight2 = 30;
   const int kMarginTop = 5;
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(100), NGSizeIndefinite));
 
   RefPtr<NGPhysicalBoxFragment> frag =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   EXPECT_EQ(LayoutUnit(kWidth), frag->Width());
   EXPECT_EQ(LayoutUnit(kHeight1 + kHeight2 + kMarginTop), frag->Height());
   EXPECT_EQ(NGPhysicalFragment::kFragmentBox, frag->Type());
   ASSERT_EQ(frag->Children().size(), 2UL);
 
   const NGPhysicalFragment* first_child_fragment = frag->Children()[0].get();
   EXPECT_EQ(kHeight1, first_child_fragment->Height());
   EXPECT_EQ(0, first_child_fragment->TopOffset());
 
@@ skipping 18 matching lines @@
       <div id="div1" style="writing-mode: vertical-lr;">
         <div id="div2">
         </div>
       </div>
     </div>
   )HTML");
   const int kHeight = 50;
   const int kMarginLeft = 100;
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space =
+  RefPtr<NGConstraintSpace> space =
       ConstructConstraintSpace(kHorizontalTopBottom, TextDirection::kLtr,
                                NGLogicalSize(LayoutUnit(500), LayoutUnit(500)));
   RefPtr<NGPhysicalBoxFragment> frag =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   const NGPhysicalFragment* child = frag->Children()[0].get();
   // DIV2
   child = static_cast<const NGPhysicalBoxFragment*>(child)->Children()[0].get();
 
   EXPECT_EQ(kHeight, child->Height());
   EXPECT_EQ(0, child->TopOffset());
   EXPECT_EQ(kMarginLeft, child->LeftOffset());
 }
 
@@ skipping 30 matching lines @@
         }
       </style>
       <div id='container'>
         <div id='float-child-left'></div>
         <div id='float-child-right'></div>
         <div id='first-child'></div>
       </div>
     )HTML");
 
   // ** Run LayoutNG algorithm **
-  NGConstraintSpace* space;
+  RefPtr<NGConstraintSpace> space;
   RefPtr<NGPhysicalBoxFragment> fragment;
   std::tie(fragment, space) = RunBlockLayoutAlgorithmForElement(
       document().getElementsByTagName("html")->item(0));
   ASSERT_EQ(fragment->Children().size(), 1UL);
   auto* body_fragment = toNGPhysicalBoxFragment(fragment->Children()[0].get());
   // 20 = max(first child's margin top, containers's margin top)
   int body_top_offset = 20;
   EXPECT_THAT(LayoutUnit(body_top_offset), body_fragment->TopOffset());
   // 8 = body's margin
   int body_left_offset = 8;
@@ skipping 98 matching lines @@
       <div id='float-between-nonempties'></div>
       <div id='second-child'>
         <div id='float-top-align'></div>
         <div id='empty3'></div>
         <div id='empty4' style='margin-top: -30px'></div>
       </div>
       <div id='empty5'></div>
     )HTML");
 
   // ** Run LayoutNG algorithm **
-  NGConstraintSpace* space;
+  RefPtr<NGConstraintSpace> space;
   RefPtr<NGPhysicalBoxFragment> fragment;
   std::tie(fragment, space) = RunBlockLayoutAlgorithmForElement(
       document().getElementsByTagName("html")->item(0));
 
   auto* body_fragment = toNGPhysicalBoxFragment(fragment->Children()[0].get());
   // -7 = empty1's margin(-15) + body's margin(8)
   int body_top_offset = -7;
   EXPECT_THAT(LayoutUnit(body_top_offset), body_fragment->TopOffset());
   int body_left_offset = 8;
   EXPECT_THAT(LayoutUnit(body_top_offset), body_fragment->TopOffset());
@@ skipping 304 matching lines @@
          <div id="div2">vertical</div>
       </div>
       <div id="div3"></div>
     </div>
   )HTML");
   const int kHeight = 60;
   const int kMarginBottom = 10;
   const int kMarginTop = 40;
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space =
+  RefPtr<NGConstraintSpace> space =
       ConstructConstraintSpace(kHorizontalTopBottom, TextDirection::kLtr,
                                NGLogicalSize(LayoutUnit(500), LayoutUnit(500)));
   RefPtr<NGPhysicalBoxFragment> frag =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   ASSERT_EQ(frag->Children().size(), 2UL);
 
   const NGPhysicalFragment* child1 = frag->Children()[0].get();
   EXPECT_EQ(0, child1->TopOffset());
   EXPECT_EQ(kHeight, child1->Height());
 
   const NGPhysicalFragment* child2 = frag->Children()[1].get();
   EXPECT_EQ(kHeight + std::max(kMarginBottom, kMarginTop), child2->TopOffset());
 }
@@ skipping 23 matching lines @@
   const int kBorderRight = 2;
   const int kBorderBottom = 3;
   const int kBorderLeft = 4;
   const int kPaddingTop = 5;
   const int kPaddingRight = 6;
   const int kPaddingBottom = 7;
   const int kPaddingLeft = 8;
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
 
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
 
   RefPtr<NGPhysicalBoxFragment> frag =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   ASSERT_EQ(frag->Children().size(), 1UL);
 
   // div1
   const NGPhysicalFragment* child = frag->Children()[0].get();
   EXPECT_EQ(kBorderLeft + kPaddingLeft + kWidth + kPaddingRight + kBorderRight,
             child->Width());
   EXPECT_EQ(kBorderTop + kPaddingTop + kHeight + kPaddingBottom + kBorderBottom,
             child->Height());
 
@@ skipping 11 matching lines @@
   setBodyInnerHTML(R"HTML(
     <div id="container" style="width: 30px; padding-left: 10px">
       <div id="div1" style="width: 40%"></div>
     </div>
   )HTML");
   const int kPaddingLeft = 10;
   const int kWidth = 30;
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
 
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(100), NGSizeIndefinite));
   RefPtr<NGPhysicalBoxFragment> frag =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   EXPECT_EQ(LayoutUnit(kWidth + kPaddingLeft), frag->Width());
   EXPECT_EQ(NGPhysicalFragment::kFragmentBox, frag->Type());
   ASSERT_EQ(frag->Children().size(), 1UL);
 
   const NGPhysicalFragment* child = frag->Children()[0].get();
   EXPECT_EQ(LayoutUnit(12), child->Width());
 }
 
 // A very simple auto margin case. We rely on the tests in ng_length_utils_test
 // for the more complex cases; just make sure we handle auto at all here.
 TEST_F(NGBlockLayoutAlgorithmTest, AutoMargin) {
   setBodyInnerHTML(R"HTML(
     <style>
       #first { width: 10px; margin-left: auto; margin-right: auto; }
     </style>
     <div id="container" style="width: 30px; padding-left: 10px">
       <div id="first">
       </div>
     </div>
   )HTML");
   const int kPaddingLeft = 10;
   const int kWidth = 30;
   const int kChildWidth = 10;
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
 
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(100), NGSizeIndefinite));
   RefPtr<NGPhysicalBoxFragment> frag =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   EXPECT_EQ(LayoutUnit(kWidth + kPaddingLeft), frag->Width());
   EXPECT_EQ(NGPhysicalFragment::kFragmentBox, frag->Type());
   EXPECT_EQ(LayoutUnit(kWidth + kPaddingLeft), frag->WidthOverflow());
   ASSERT_EQ(1UL, frag->Children().size());
 
   const NGPhysicalFragment* child = frag->Children()[0].get();
   EXPECT_EQ(LayoutUnit(kChildWidth), child->Width());
   EXPECT_EQ(LayoutUnit(kPaddingLeft + 10), child->LeftOffset());
   EXPECT_EQ(LayoutUnit(0), child->TopOffset());
@@ skipping 37 matching lines @@
         <div id='empty1'>
           <div id='empty2'>
             <div id='left-float'></div>
             <div id='right-float'></div>
           </div>
         </div>
       </div>
     )HTML");
 
   // ** Run LayoutNG algorithm **
-  NGConstraintSpace* space;
+  RefPtr<NGConstraintSpace> space;
   RefPtr<NGPhysicalBoxFragment> fragment;
   std::tie(fragment, space) = RunBlockLayoutAlgorithmForElement(
       document().getElementsByTagName("html")->item(0));
 
   auto* body_fragment = toNGPhysicalBoxFragment(fragment->Children()[0].get());
   // 20 = std::max(empty1's margin, empty2's margin, body's margin)
   int body_top_offset = 20;
   EXPECT_THAT(LayoutUnit(body_top_offset), body_fragment->TopOffset());
   ASSERT_EQ(1UL, body_fragment->Children().size());
   auto* container_fragment =
@@ skipping 112 matching lines @@
       <div id='container'>
         <div id='left-float'></div>
         <div id='left-wide-float'></div>
         <div id='regular'></div>
         <div id='right-float'></div>
         <div id='left-float-with-margin'></div>
       </div>
       )HTML");
 
   // ** Run LayoutNG algorithm **
-  NGConstraintSpace* space;
+  RefPtr<NGConstraintSpace> space;
   RefPtr<NGPhysicalBoxFragment> fragment;
   std::tie(fragment, space) = RunBlockLayoutAlgorithmForElement(
       document().getElementsByTagName("html")->item(0));
 
   // ** Verify LayoutNG fragments and the list of positioned floats **
   ASSERT_EQ(1UL, fragment->Children().size());
   auto* body_fragment = toNGPhysicalBoxFragment(fragment->Children()[0].get());
   EXPECT_THAT(LayoutUnit(8), body_fragment->TopOffset());
   auto* container_fragment =
       toNGPhysicalBoxFragment(body_fragment->Children()[0].get());
@@ skipping 260 matching lines @@
   setBodyInnerHTML(R"HTML(
     <div id="container">
       <div id="first-child" style="width: 20px"></div>
       <div id="second-child" style="width: 30px"></div>
     </div>
   )HTML");
   const int kWidthChild2 = 30;
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
 
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(100), NGSizeIndefinite), true);
-  RefPtr<NGPhysicalFragment> frag = RunBlockLayoutAlgorithm(space, container);
+  RefPtr<NGPhysicalFragment> frag =
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   EXPECT_EQ(LayoutUnit(kWidthChild2), frag->Width());
 }
 
 class FragmentChildIterator {
   STACK_ALLOCATED();
 
  public:
   explicit FragmentChildIterator(const NGPhysicalBoxFragment* parent) {
     SetParent(parent);
@@ skipping 35 matching lines @@
         width: 210px;
       }
     </style>
     <div id="container">
       <div id="parent">
       </div>
     </div>
   )HTML");
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
   RefPtr<const NGPhysicalBoxFragment> parent_fragment =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
   FragmentChildIterator iterator(parent_fragment.get());
   const auto* fragment = iterator.NextChild();
   ASSERT_TRUE(fragment);
   EXPECT_EQ(LayoutUnit(210), fragment->Width());
   EXPECT_EQ(LayoutUnit(100), fragment->Height());
   EXPECT_FALSE(iterator.NextChild());
 
   // There should be nothing inside the multicol container.
   EXPECT_FALSE(FragmentChildIterator(fragment).NextChild());
 }
@@ skipping 10 matching lines @@
     </style>
     <div id="container">
       <div id="parent">
         <div id="child">
         </div>
       </div>
     </div>
   )HTML");
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
   RefPtr<const NGPhysicalBoxFragment> parent_fragment =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
   FragmentChildIterator iterator(parent_fragment.get());
   const auto* fragment = iterator.NextChild();
   EXPECT_EQ(LayoutUnit(210), fragment->Width());
   EXPECT_EQ(LayoutUnit(100), fragment->Height());
   ASSERT_TRUE(fragment);
   EXPECT_FALSE(iterator.NextChild());
   iterator.SetParent(fragment);
 
   // #child fragment in first column
   fragment = iterator.NextChild();
@@ skipping 21 matching lines @@
     </style>
     <div id="container">
       <div id="parent">
         <div id="child" style="width: 60%; height: 100%">
         </div>
       </div>
     </div>
   )HTML");
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
   RefPtr<const NGPhysicalBoxFragment> parent_fragment =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   FragmentChildIterator iterator(parent_fragment.get());
   const auto* fragment = iterator.NextChild();
   ASSERT_TRUE(fragment);
   EXPECT_EQ(LayoutUnit(310), fragment->Width());
   EXPECT_EQ(LayoutUnit(100), fragment->Height());
   EXPECT_FALSE(iterator.NextChild());
   iterator.SetParent(fragment);
 
   // #child fragment in first column
@@ skipping 21 matching lines @@
       }
     </style>
     <div id="container">
       <div id="parent">
         <div id="child" style="width: 75%; height: 150px"></div>
       </div>
     </div>
   )HTML");
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
   RefPtr<const NGPhysicalBoxFragment> parent_fragment =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   FragmentChildIterator iterator(parent_fragment.get());
   const auto* fragment = iterator.NextChild();
   ASSERT_TRUE(fragment);
   EXPECT_EQ(LayoutUnit(210), fragment->Width());
   EXPECT_EQ(LayoutUnit(100), fragment->Height());
   EXPECT_FALSE(iterator.NextChild());
 
   iterator.SetParent(fragment);
   // #child fragment in first column
@@ skipping 31 matching lines @@
     </style>
     <div id="container">
       <div id="parent">
         <div id="child" style="width: 75%; height: 250px;">
         </div>
       </div>
     </div>
   )HTML");
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
   RefPtr<const NGPhysicalBoxFragment> parent_fragment =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   FragmentChildIterator iterator(parent_fragment.get());
   const auto* fragment = iterator.NextChild();
   ASSERT_TRUE(fragment);
   EXPECT_EQ(LayoutUnit(320), fragment->Width());
   EXPECT_EQ(LayoutUnit(100), fragment->Height());
   EXPECT_FALSE(iterator.NextChild());
 
   iterator.SetParent(fragment);
   // #child fragment in first column
@@ skipping 41 matching lines @@
     </style>
     <div id="container">
       <div id="parent">
         <div id="child" style="width: 1px; height: 250px;">
         </div>
       </div>
     </div>
   )HTML");
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
   RefPtr<const NGPhysicalBoxFragment> parent_fragment =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   FragmentChildIterator iterator(parent_fragment.get());
   const auto* fragment = iterator.NextChild();
   ASSERT_TRUE(fragment);
   EXPECT_EQ(LayoutUnit(210), fragment->Width());
   EXPECT_EQ(LayoutUnit(100), fragment->Height());
   EXPECT_FALSE(iterator.NextChild());
 
   iterator.SetParent(fragment);
   // #child fragment in first column
@@ skipping 42 matching lines @@
       <div id="parent">
         <div id="child1" style="width: 75%; height: 60px;">
         </div>
         <div id="child2" style="width: 85%; height: 60px;">
         </div>
       </div>
     </div>
   )HTML");
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
   RefPtr<const NGPhysicalBoxFragment> parent_fragment =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   FragmentChildIterator iterator(parent_fragment.get());
   const auto* fragment = iterator.NextChild();
   ASSERT_TRUE(fragment);
   EXPECT_EQ(LayoutUnit(320), fragment->Width());
   EXPECT_EQ(LayoutUnit(100), fragment->Height());
   EXPECT_FALSE(iterator.NextChild());
 
   iterator.SetParent(fragment);
   // #child1 fragment in first column
@@ skipping 45 matching lines @@
           <div id="grandchild2" style="width: 40px; height: 20px;">
           </div>
         </div>
         <div id="child2" style="width: 85%; height: 10px;"></div>
         </div>
       </div>
     </div>
   )HTML");
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
   RefPtr<const NGPhysicalBoxFragment> parent_fragment =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   FragmentChildIterator iterator(parent_fragment.get());
   const auto* fragment = iterator.NextChild();
   ASSERT_TRUE(fragment);
   EXPECT_EQ(LayoutUnit(320), fragment->Width());
   EXPECT_EQ(LayoutUnit(100), fragment->Height());
   EXPECT_FALSE(iterator.NextChild());
 
   iterator.SetParent(fragment);
   // #child1 fragment in first column
@@ skipping 62 matching lines @@
     </style>
     <div id="container">
       <div id="parent">
         <div id="child" style="float: left; width: 75%; height: 100px;">
         </div>
       </div>
     </div>
   )HTML");
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
   RefPtr<const NGPhysicalBoxFragment> parent_fragment =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   FragmentChildIterator iterator(parent_fragment.get());
   const auto* fragment = iterator.NextChild();
   ASSERT_TRUE(fragment);
   EXPECT_EQ(LayoutUnit(320), fragment->Width());
   EXPECT_EQ(LayoutUnit(100), fragment->Height());
   EXPECT_FALSE(iterator.NextChild());
 
   iterator.SetParent(fragment);
   // #child fragment in first column
@@ skipping 24 matching lines @@
       <div id="parent">
         <div id="child1" style="float: left; width: 15%; height: 100px;">
         </div>
         <div id="child2" style="float: right; width: 16%; height: 100px;">
         </div>
       </div>
     </div>
   )HTML");
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
   RefPtr<const NGPhysicalBoxFragment> parent_fragment =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   FragmentChildIterator iterator(parent_fragment.get());
   const auto* fragment = iterator.NextChild();
   ASSERT_TRUE(fragment);
   EXPECT_EQ(LayoutUnit(320), fragment->Width());
   EXPECT_EQ(LayoutUnit(100), fragment->Height());
   EXPECT_FALSE(iterator.NextChild());
 
   iterator.SetParent(fragment);
   // #child1 fragment in first column
@@ skipping 32 matching lines @@
       <div id="parent">
         <div id="child1" style="float: left; width: 15%; height: 150px;">
         </div>
         <div id="child2" style="float: right; width: 16%; height: 150px;">
         </div>
       </div>
     </div>
   )HTML");
 
   auto* container = new NGBlockNode(getLayoutObjectByElementId("container"));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite));
   RefPtr<const NGPhysicalBoxFragment> parent_fragment =
-      RunBlockLayoutAlgorithm(space, container);
+      RunBlockLayoutAlgorithm(space.get(), container);
 
   FragmentChildIterator iterator(parent_fragment.get());
   const auto* fragment = iterator.NextChild();
   ASSERT_TRUE(fragment);
   EXPECT_EQ(LayoutUnit(320), fragment->Width());
   EXPECT_EQ(LayoutUnit(100), fragment->Height());
   EXPECT_FALSE(iterator.NextChild());
 
   iterator.SetParent(fragment);
   // #child1 fragment in first column
@@ skipping 180 matching lines @@
           height: 200px;
         }
       </style>
       <div id='container'></div>
   )HTML");
 
   LayoutUnit kFragmentainerSpaceAvailable(200);
 
   NGBlockNode* node = new NGBlockNode(
       toLayoutBlockFlow(getLayoutObjectByElementId("container")));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite), false,
       kFragmentainerSpaceAvailable);
 
   // We should only have one 150x200 fragment with no fragmentation.
   RefPtr<const NGPhysicalFragment> fragment =
-      NGBlockLayoutAlgorithm(node, space).Layout()->PhysicalFragment();
+      NGBlockLayoutAlgorithm(node, space.get()).Layout()->PhysicalFragment();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(200)), fragment->Size());
   ASSERT_TRUE(fragment->BreakToken()->IsFinished());
 }
 
 // Tests that a block will fragment if it reaches the fragmentation line.
 TEST_F(NGBlockLayoutAlgorithmTest, SimpleFragmentation) {
   setBodyInnerHTML(R"HTML(
       <!DOCTYPE html>
       <style>
         #container {
           width: 150px;
           height: 300px;
         }
       </style>
       <div id='container'></div>
   )HTML");
 
   LayoutUnit kFragmentainerSpaceAvailable(200);
 
   NGBlockNode* node = new NGBlockNode(
       toLayoutBlockFlow(getLayoutObjectByElementId("container")));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite), false,
       kFragmentainerSpaceAvailable);
 
   RefPtr<const NGPhysicalFragment> fragment =
-      NGBlockLayoutAlgorithm(node, space).Layout()->PhysicalFragment();
+      NGBlockLayoutAlgorithm(node, space.get()).Layout()->PhysicalFragment();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(200)), fragment->Size());
   ASSERT_FALSE(fragment->BreakToken()->IsFinished());
 
-  fragment = NGBlockLayoutAlgorithm(node, space,
+  fragment = NGBlockLayoutAlgorithm(node, space.get(),
                                     toNGBlockBreakToken(fragment->BreakToken()))
                  .Layout()
                  ->PhysicalFragment();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(100)), fragment->Size());
   ASSERT_TRUE(fragment->BreakToken()->IsFinished());
 }
 
 // Tests that children inside the same block formatting context fragment when
 // reaching a fragmentation line.
 TEST_F(NGBlockLayoutAlgorithmTest, InnerChildrenFragmentation) {
@@ skipping 16 matching lines @@
       <div id='container'>
         <div id='child1'></div>
         <div id='child2'></div>
       </div>
   )HTML");
 
   LayoutUnit kFragmentainerSpaceAvailable(200);
 
   NGBlockNode* node = new NGBlockNode(
       toLayoutBlockFlow(getLayoutObjectByElementId("container")));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite), false,
       kFragmentainerSpaceAvailable);
 
   RefPtr<const NGPhysicalFragment> fragment =
-      NGBlockLayoutAlgorithm(node, space).Layout()->PhysicalFragment();
+      NGBlockLayoutAlgorithm(node, space.get()).Layout()->PhysicalFragment();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(200)), fragment->Size());
   ASSERT_FALSE(fragment->BreakToken()->IsFinished());
 
   FragmentChildIterator iterator(toNGPhysicalBoxFragment(fragment.get()));
   const NGPhysicalBoxFragment* child = iterator.NextChild();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(180)), child->Size());
   EXPECT_EQ(NGPhysicalOffset(LayoutUnit(0), LayoutUnit(20)), child->Offset());
 
   EXPECT_FALSE(iterator.NextChild());
 
-  fragment = NGBlockLayoutAlgorithm(node, space,
+  fragment = NGBlockLayoutAlgorithm(node, space.get(),
                                     toNGBlockBreakToken(fragment->BreakToken()))
                  .Layout()
                  ->PhysicalFragment();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(140)), fragment->Size());
   ASSERT_TRUE(fragment->BreakToken()->IsFinished());
 
   iterator.SetParent(toNGPhysicalBoxFragment(fragment.get()));
   child = iterator.NextChild();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(20)), child->Size());
   EXPECT_EQ(NGPhysicalOffset(LayoutUnit(0), LayoutUnit(0)), child->Offset());
@@ skipping 30 matching lines @@
       <div id='container'>
         <div id='child1'></div>
         <div id='child2'></div>
       </div>
   )HTML");
 
   LayoutUnit kFragmentainerSpaceAvailable(200);
 
   NGBlockNode* node = new NGBlockNode(
       toLayoutBlockFlow(getLayoutObjectByElementId("container")));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite), false,
       kFragmentainerSpaceAvailable);
 
   RefPtr<const NGPhysicalFragment> fragment =
-      NGBlockLayoutAlgorithm(node, space).Layout()->PhysicalFragment();
+      NGBlockLayoutAlgorithm(node, space.get()).Layout()->PhysicalFragment();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(200)), fragment->Size());
   ASSERT_FALSE(fragment->BreakToken()->IsFinished());
 
   FragmentChildIterator iterator(toNGPhysicalBoxFragment(fragment.get()));
   const NGPhysicalBoxFragment* child = iterator.NextChild();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(180)), child->Size());
   EXPECT_EQ(NGPhysicalOffset(LayoutUnit(0), LayoutUnit(20)), child->Offset());
 
   EXPECT_FALSE(iterator.NextChild());
 
-  fragment = NGBlockLayoutAlgorithm(node, space,
+  fragment = NGBlockLayoutAlgorithm(node, space.get(),
                                     toNGBlockBreakToken(fragment->BreakToken()))
                  .Layout()
                  ->PhysicalFragment();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(140)), fragment->Size());
   ASSERT_TRUE(fragment->BreakToken()->IsFinished());
 
   iterator.SetParent(toNGPhysicalBoxFragment(fragment.get()));
   child = iterator.NextChild();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(20)), child->Size());
   EXPECT_EQ(NGPhysicalOffset(LayoutUnit(0), LayoutUnit(0)), child->Offset());
@@ skipping 28 matching lines @@
       <div id='container'>
         <div id='child1'></div>
         <div id='child2'></div>
       </div>
   )HTML");
 
   LayoutUnit kFragmentainerSpaceAvailable(200);
 
   NGBlockNode* node = new NGBlockNode(
       toLayoutBlockFlow(getLayoutObjectByElementId("container")));
-  auto* space = ConstructConstraintSpace(
+  RefPtr<NGConstraintSpace> space = ConstructConstraintSpace(
       kHorizontalTopBottom, TextDirection::kLtr,
       NGLogicalSize(LayoutUnit(1000), NGSizeIndefinite), false,
       kFragmentainerSpaceAvailable);
 
   RefPtr<const NGPhysicalFragment> fragment =
-      NGBlockLayoutAlgorithm(node, space).Layout()->PhysicalFragment();
+      NGBlockLayoutAlgorithm(node, space.get()).Layout()->PhysicalFragment();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(70)), fragment->Size());
   ASSERT_FALSE(fragment->BreakToken()->IsFinished());
 
   FragmentChildIterator iterator(toNGPhysicalBoxFragment(fragment.get()));
   const NGPhysicalBoxFragment* child = iterator.NextChild();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(180)), child->Size());
   EXPECT_EQ(NGPhysicalOffset(LayoutUnit(0), LayoutUnit(20)), child->Offset());
 
   EXPECT_FALSE(iterator.NextChild());
 
-  fragment = NGBlockLayoutAlgorithm(node, space,
+  fragment = NGBlockLayoutAlgorithm(node, space.get(),
                                     toNGBlockBreakToken(fragment->BreakToken()))
                  .Layout()
                  ->PhysicalFragment();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(0)), fragment->Size());
   ASSERT_TRUE(fragment->BreakToken()->IsFinished());
 
   iterator.SetParent(toNGPhysicalBoxFragment(fragment.get()));
   child = iterator.NextChild();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(20)), child->Size());
   EXPECT_EQ(NGPhysicalOffset(LayoutUnit(0), LayoutUnit(0)), child->Offset());
 
   child = iterator.NextChild();
   EXPECT_EQ(NGPhysicalSize(LayoutUnit(150), LayoutUnit(100)), child->Size());
   EXPECT_EQ(NGPhysicalOffset(LayoutUnit(0), LayoutUnit(40)), child->Offset());
 
   EXPECT_FALSE(iterator.NextChild());
 }
 
 }  // namespace
 }  // namespace blink