Revert of Refactor avoidsFloats() to reflect CSS2.1 spec more clearly

Source/core/rendering/RenderBlock.cpp

Index: Source/core/rendering/RenderBlock.cpp
diff --git a/Source/core/rendering/RenderBlock.cpp b/Source/core/rendering/RenderBlock.cpp
index cb9767025d61e4116a41194b137cd10b61dd9515..ad231810717c6dc5d1c696dfd397f4c5d0d82e81 100644
--- a/Source/core/rendering/RenderBlock.cpp
+++ b/Source/core/rendering/RenderBlock.cpp
@@ -1512,6 +1512,12 @@
     addVisualOverflow(inflatedRect);
 }
 
+bool RenderBlock::createsBlockFormattingContext() const
+{
+    return isInlineBlockOrInlineTable() || isFloatingOrOutOfFlowPositioned() || hasOverflowClip() || isFlexItemIncludingDeprecated()
+        || style()->specifiesColumns() || isRenderFlowThread() || isTableCell() || isTableCaption() || isFieldset() || isWritingModeRoot() || isDocumentElement() || style()->columnSpan();
+}
+
 void RenderBlock::updateBlockChildDirtyBitsBeforeLayout(bool relayoutChildren, RenderBox* child)
 {
     // FIXME: Technically percentage height objects only need a relayout if their percentage isn't going to be turned into
@@ -2757,6 +2763,12 @@
         afterLowest->markDirty();
         afterLowest = afterLowest->prevRootBox();
     }
+}
+
+bool RenderBlock::avoidsFloats() const
+{
+    // Floats can't intrude into our box if we have a non-auto column count or width.
+    return RenderBox::avoidsFloats() || !style()->hasAutoColumnCount() || !style()->hasAutoColumnWidth();
 }
 
 bool RenderBlock::isPointInOverflowControl(HitTestResult& result, const LayoutPoint& locationInContainer, const LayoutPoint& accumulatedOffset)