Add ClearanceOffset to LayoutNG Constraint space.

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

Index: third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.h b/third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.h
index 74365e488fe43b3c00cdcd0adb8695e4f5125797..0d7389af9b0b6bf563c31ab8be558794f5e6bb1a 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.h
@@ -40,6 +40,9 @@ class CORE_EXPORT NGBlockLayoutAlgorithm : public NGLayoutAlgorithm {
   RefPtr<NGPhysicalFragment> Layout() override;
 
  private:
+  // Updates the fragment's BFC offset if it's not already set.

[ikilpatrick, 2017/02/24 17:36:57]

I might go through later and reorder everything so it roughly matches the cc
file. We are a little all over the place at the moment.

[Gleb Lanbin, 2017/02/24 18:37:00]

agree, I tried to organize things here (see "Read-only Getters" section for
example) in the past but we need all agree how we want to group methods. I like
Oracle java guideline
https://web.archive.org/web/20130627193836/http://www.oracle.com/technetwork/...
We can try to follow it here. For now I just moved this method closed to the end
before "getters" section.

+  void UpdateFragmentBfcOffset(const NGLogicalOffset& offset);
+
   NGBoxStrut CalculateMargins(const NGConstraintSpace& space,
                               const ComputedStyle& style);