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

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

Index: third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
index 8fa39a5c14e57891d8c5695f4375d5eca196f561..02a8c9acce0f77460fd29ab3e092589bec20c118 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
@@ -233,8 +233,10 @@ void LayoutBlockFlow::checkForPaginationLogicalHeightChange(LayoutUnit& pageLogi
         // don't know the actual height of the content yet, only call that method when height is
         // definite, or we might fool ourselves into believing that columns have a definite height
         // when they in fact don't.
+        // To check if we've a definite height we verify that percentage height is resolvable
+        // on the first in-flow child.
         LayoutUnit columnHeight;
-        if (hasDefiniteLogicalHeight() || isLayoutView()) {
+        if (!firstInFlowChildBox() || firstInFlowChildBox()->percentageLogicalHeightIsResolvable() || isLayoutView()) {
             LogicalExtentComputedValues computedValues;
             computeLogicalHeight(LayoutUnit(), logicalTop(), computedValues);
             columnHeight = computedValues.m_extent - borderAndPaddingLogicalHeight() - scrollbarLogicalHeight();