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

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

Index: third_party/WebKit/Source/core/layout/LayoutGrid.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
index 7bf340f7cfcc26b830b9dddb86589a4ab5cefcb3..42b653c95eb54e4414c89f684a003bf87686a89f 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
@@ -750,7 +750,8 @@ GridTrackSize LayoutGrid::gridTrackSize(GridTrackSizingDirection direction, size
 
     // If the logical width/height of the grid container is indefinite, percentage values are treated as <auto>.
     // For the inline axis this only happens when we're computing the intrinsic sizes (AvailableSpaceIndefinite).
-    if (sizingOperation == IntrinsicSizeComputation || (direction == ForRows && !hasDefiniteLogicalHeight())) {
+    // For the block axis we check that the percentage height is resolvable on the first in-flow child.
+    if ((sizingOperation == IntrinsicSizeComputation) || (direction == ForRows && firstInFlowChildBox() && !firstInFlowChildBox()->percentageLogicalHeightIsResolvable())) {
         if (minTrackBreadth.hasPercentage())
             minTrackBreadth = Length(Auto);
         if (maxTrackBreadth.hasPercentage())