[layoutng] Support computing min-content and max-content

third_party/WebKit/Source/core/layout/ng/ng_box.h

Index: third_party/WebKit/Source/core/layout/ng/ng_box.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_box.h b/third_party/WebKit/Source/core/layout/ng/ng_box.h
index a402ad24c2b1cde35a50da3d5d4b05ffe32b9f1e..1292b2d9975d1acfc5cd902c20524591392eb718 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_box.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_box.h
@@ -13,10 +13,11 @@ namespace blink {
 class ComputedStyle;
 class LayoutBox;
 class LayoutObject;
-class NGBlockLayoutAlgorithm;
 class NGConstraintSpace;
 class NGFragment;
+class NGLayoutAlgorithm;
 class NGPhysicalFragment;
+struct MinAndMaxContentSizes;
 
 // Represents a node to be laid out.
 class CORE_EXPORT NGBox final : public GarbageCollectedFinalized<NGBox> {
@@ -32,6 +33,18 @@ class CORE_EXPORT NGBox final : public GarbageCollectedFinalized<NGBox> {
   // TODO(layout-ng): Should we have a StartLayout function to avoid passing
   // the same space for each Layout iteration?
   bool Layout(const NGConstraintSpace*, NGFragment**);
+
+  // Computes the value of min-content and max-content for this box.
+  // The return value has the same meaning as for Layout.
+  // If the underlying layout algorithm returns NotImplemented from
+  // ComputeMinAndMaxContentSizes, this function will synthesize these sizes
+  // using Layout with special constraint spaces.
+  // It is not legal to interleave a pending Layout() with a pending
+  // ComputeOrSynthesizeMinAndMaxContentSizes (i.e. you have to call Layout
+  // often enough that it returns true before calling
+  // ComputeOrSynthesizeMinAndMaxContentSizes)
+  bool ComputeMinAndMaxContentSizes(MinAndMaxContentSizes*);
+
   const ComputedStyle* Style() const;
 
   NGBox* NextSibling();
@@ -41,12 +54,7 @@ class CORE_EXPORT NGBox final : public GarbageCollectedFinalized<NGBox> {
   void SetNextSibling(NGBox*);
   void SetFirstChild(NGBox*);
 
-  DEFINE_INLINE_VIRTUAL_TRACE() {
-    visitor->trace(algorithm_);
-    visitor->trace(fragment_);
-    visitor->trace(next_sibling_);
-    visitor->trace(first_child_);
-  }
+  DECLARE_VIRTUAL_TRACE();
 
  private:
   // This is necessary for interop between old and new trees -- after our parent
@@ -70,7 +78,8 @@ class CORE_EXPORT NGBox final : public GarbageCollectedFinalized<NGBox> {
   RefPtr<ComputedStyle> style_;
   Member<NGBox> next_sibling_;
   Member<NGBox> first_child_;
-  Member<NGBlockLayoutAlgorithm> algorithm_;
+  Member<NGLayoutAlgorithm> layout_algorithm_;
+  Member<NGLayoutAlgorithm> minmax_algorithm_;
   Member<NGPhysicalFragment> fragment_;
 };