[css-grid] Fix definite/indefinite size detection on block axis

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

Index: third_party/WebKit/Source/core/layout/LayoutBox.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutBox.h b/third_party/WebKit/Source/core/layout/LayoutBox.h
index db613b53a1d742b4be8e9188a40ea2c221530ef9..da79f2cdaca866e52e19c5649a52ccb1a412194e 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBox.h
+++ b/third_party/WebKit/Source/core/layout/LayoutBox.h
@@ -199,6 +199,7 @@ public:
 
     // Use this with caution! No type checking is done!
     LayoutBox* firstChildBox() const;
+    LayoutBox* firstInFlowChildBox() const;
     LayoutBox* lastChildBox() const;
 
     int pixelSnappedWidth() const { return m_frameRect.pixelSnappedWidth(); }
@@ -740,7 +741,6 @@ public:
 
     bool hasDefiniteLogicalWidth() const;
     bool percentageLogicalHeightIsResolvable() const;
-    bool hasDefiniteLogicalHeight() const;
     LayoutUnit computePercentageLogicalHeight(const Length& height) const;
 
     // Block flows subclass availableWidth/Height to handle multi column layout (shrinking the width/height available to children when laying out.)
@@ -1170,6 +1170,14 @@ inline LayoutBox* LayoutBox::firstChildBox() const
     return toLayoutBox(slowFirstChild());
 }
 
+inline LayoutBox* LayoutBox::firstInFlowChildBox() const
+{
+    LayoutBox* child = firstChildBox();
+    while (child && child->isOutOfFlowPositioned())
+        child = child->nextSiblingBox();
+    return child;
+}
+
 inline LayoutBox* LayoutBox::lastChildBox() const
 {
     return toLayoutBox(slowLastChild());