Revert of Add grid/flex layout support for <fieldset>

third_party/WebKit/Source/core/layout/LayoutBlock.cpp

Index: third_party/WebKit/Source/core/layout/LayoutBlock.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
index 0a387ddc25d4876e42721d0d67e1d5c873cfbf35..88c0166f0b993a1083e9301a771162f982c0cb5a 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
@@ -1736,9 +1736,6 @@
     if (display == FLEX || display == INLINE_FLEX) {
         newBox = LayoutFlexibleBox::createAnonymous(&parent->document());
         newDisplay = FLEX;
-    } else if (display == GRID || display == INLINE_GRID) {
-        newBox = LayoutGrid::createAnonymous(&parent->document());
-        newDisplay = GRID;
     } else {
         newBox = LayoutBlockFlow::createAnonymous(&parent->document());
         newDisplay = BLOCK;