[LayoutNG] Fix orthogonal writing mode child margin strut from being used in collapsing margins cal…

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

Index: third_party/WebKit/Source/core/layout/ng/ng_fragment.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_fragment.cc b/third_party/WebKit/Source/core/layout/ng/ng_fragment.cc
index 4085e380af9aea6c8746769477c7eb5125ff9ab5..0b59fba6d135112f3707d07e285f1a76dfd5d5a6 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_fragment.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_fragment.cc
@@ -4,4 +4,16 @@
 
 #include "core/layout/ng/ng_fragment.h"
 
-namespace blink {}  // namespace blink
+#include "core/layout/ng/ng_physical_fragment.h"
+
+namespace blink {
+
+NGMarginStrut NGFragment::MarginStrut() const {
+  return writing_mode_ ==

[Gleb Lanbin, 2016/10/13 23:59:51]

it's better to use IF instead of a long ternary operator here. 

+                 toNGPhysicalFragment(physical_fragment_)
+                     ->MarginStrutWritingMode()
+             ? toNGPhysicalFragment(physical_fragment_)->MarginStrut()

[Gleb Lanbin, 2016/10/13 23:59:51]

toNGPhysicalFragment(physical_fragment_)->MarginStrut() is a bit wordy way to
access MarginStrut, should we keep it in the base instead ?

+             : NGMarginStrut();
+}
+
+}  // namespace blink