Implement Layout Containment

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

Index: third_party/WebKit/Source/core/layout/LayoutBox.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBox.cpp b/third_party/WebKit/Source/core/layout/LayoutBox.cpp
index f8986d141ca7888851c88322342aabb4c99afd06..d6460b0f6535dde544c7d6903d8edba2aa4afb82 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBox.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBox.cpp
@@ -2064,7 +2064,7 @@ static float getMaxWidthListMarker(const LayoutBox* layoutObject)
 
 void LayoutBox::computeLogicalWidth(LogicalExtentComputedValues& computedValues) const
 {
-    computedValues.m_extent = logicalWidth();
+    computedValues.m_extent = style()->containsLayout() ? borderAndPaddingLogicalWidth() : logicalWidth();
     computedValues.m_position = logicalLeft();
     computedValues.m_margins.m_start = marginStart();
     computedValues.m_margins.m_end = marginEnd();
@@ -2379,7 +2379,10 @@ void LayoutBox::updateLogicalHeight()
     m_intrinsicContentLogicalHeight = contentLogicalHeight();
 
     LogicalExtentComputedValues computedValues;
-    computeLogicalHeight(logicalHeight(), logicalTop(), computedValues);
+    if (style()->containsLayout())

[ojan, 2015/12/18 18:21:14]

Nit: I might have written this as:
LayoutUnit height = style()->containsLayout() ? borderAndPaddingLogicalHeight()
: logicalHeight();
computeLogicalHeight(height, logicalTop(), computedValues);

Avoids duplicating a bit of code.

+        computeLogicalHeight(borderAndPaddingLogicalHeight(), logicalTop(), computedValues);
+    else
+        computeLogicalHeight(logicalHeight(), logicalTop(), computedValues);
 
     setLogicalHeight(computedValues.m_extent);
     setLogicalTop(computedValues.m_position);
@@ -4058,7 +4061,7 @@ static bool shouldBeConsideredAsReplaced(Node* node)
 
 bool LayoutBox::avoidsFloats() const
 {
-    return isAtomicInlineLevel() || shouldBeConsideredAsReplaced(node()) || hasOverflowClip() || isHR() || isLegend() || isWritingModeRoot() || isFlexItemIncludingDeprecated() || style()->containsPaint();
+    return isAtomicInlineLevel() || shouldBeConsideredAsReplaced(node()) || hasOverflowClip() || isHR() || isLegend() || isWritingModeRoot() || isFlexItemIncludingDeprecated() || style()->containsPaint() || style()->containsLayout();
 }
 
 bool LayoutBox::hasNonCompositedScrollbars() const