Deprecate the currently used NGMarginStrut in favor of the new one.

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

Index: third_party/WebKit/Source/core/layout/ng/ng_fragment_builder.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_fragment_builder.h b/third_party/WebKit/Source/core/layout/ng/ng_fragment_builder.h
index f9b65cdff5e974b6ae34bb5e688c1bc59d98a3f5..29e39de2bb38a8f8e512e8f12e70f41cd9df37b1 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_fragment_builder.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_fragment_builder.h
@@ -93,8 +93,10 @@ class CORE_EXPORT NGFragmentBuilder final
   bool HasBreakToken() const { return break_token_; }
 
   // Sets MarginStrut for the resultant fragment.
-  NGFragmentBuilder& SetMarginStrutBlockStart(const NGMarginStrut& from);
-  NGFragmentBuilder& SetMarginStrutBlockEnd(const NGMarginStrut& from);
+  NGFragmentBuilder& SetMarginStrutBlockStart(
+      const NGDeprecatedMarginStrut& from);
+  NGFragmentBuilder& SetMarginStrutBlockEnd(
+      const NGDeprecatedMarginStrut& from);
 
   // Offsets are not supposed to be set during fragment construction, so we
   // do not provide a setter here.
@@ -138,7 +140,7 @@ class CORE_EXPORT NGFragmentBuilder final
   NGLogicalSize size_;
   NGLogicalSize overflow_;
 
-  NGMarginStrut margin_strut_;
+  NGDeprecatedMarginStrut margin_strut_;
 
   HeapVector<Member<NGPhysicalFragment>> children_;
   Vector<NGLogicalOffset> offsets_;