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

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

Index: third_party/WebKit/Source/core/layout/ng/ng_layout_algorithm.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_layout_algorithm.h b/third_party/WebKit/Source/core/layout/ng/ng_layout_algorithm.h
index f3a0c19cd4b74751c7c9ea321eaa15fd87bb018f..f376009548438c6a6b22880fd54880c1d955f00a 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_layout_algorithm.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_layout_algorithm.h
@@ -33,6 +33,20 @@ class CORE_EXPORT NGLayoutAlgorithm
   // returns true.
   virtual bool Layout(NGPhysicalFragment**) = 0;
 
+  enum MinAndMaxState { Success, NotImplemented };

[Gleb Lanbin, 2016/10/31 19:52:47]

may be use std::optional instead of one more enum?

+
+  // Computes the min-content and max-content intrinsic sizes for the given box.
+  // The result will not take any min-width. max-width or width properties into
+  // account. Implementations can return NotImpplemented in which case the
+  // caller is expected ot synthesize this value from the overflow rect returned
+  // from Layout called with a container width of 0 and LayoutUnit::max(),
+  // respectively.
+  virtual MinAndMaxState ComputeMinAndMaxContentSizes(
+      NGFragment** min_content,
+      NGFragment** max_content) {
+    return NotImplemented;
+  }
+
   DEFINE_INLINE_VIRTUAL_TRACE() {}
 };