Reland main thread position sticky implementation.

third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp

Index: third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp b/third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp
index 0abc9433952c71d5671ab6279e906d3816ee68d6..a564db6ee4093cc0e5e177b5eb0b21755481dcfc 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp
+++ b/third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp
@@ -196,7 +196,7 @@ void StyleAdjuster::adjustComputedStyle(ComputedStyle& style, const ComputedStyl
         || style.hasFilterInducingProperty()
         || style.hasBlendMode()
         || style.hasIsolation()
-        || style.position() == FixedPosition
+        || style.hasViewportConstrainedPosition()
         || isInTopLayer(element, style)
         || hasWillChangeThatCreatesStackingContext(style)
         || style.containsPaint()))
@@ -436,6 +436,12 @@ void StyleAdjuster::adjustStyleForDisplay(ComputedStyle& style, const ComputedSt
         && style.position() == RelativePosition)
         style.setPosition(StaticPosition);
 
+    // Cannot support position: sticky for table columns and column groups because current code is only doing
+    // background painting through columns / column groups
+    if ((style.display() == TABLE_COLUMN_GROUP || style.display() == TABLE_COLUMN)
+        && style.position() == StickyPosition)
+        style.setPosition(StaticPosition);
+
     // writing-mode does not apply to table row groups, table column groups, table rows, and table columns.
     // FIXME: Table cells should be allowed to be perpendicular or flipped with respect to the table, though.
     if (style.display() == TABLE_COLUMN || style.display() == TABLE_COLUMN_GROUP || style.display() == TABLE_FOOTER_GROUP