[css-grid] Clamp the number of auto-repeat tracks

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 017e0dafe045673093764f7ac01a09e4b1f146a3..16481de35e7f39ff15dc10cffea1bf5fef404485 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
@@ -2042,6 +2042,13 @@ size_t LayoutGrid::computeAutoRepeatTracksCount(
   if (needsToFulfillMinimumSize)
     ++repetitions;
 
+  // Clamp the number of repetitions so we don't end up with too many tracks.
+  if (repetitions > kGridMaxTracks) {
+    DCHECK_GT(autoRepeatTrackListLength, 0u);
+    repetitions =
+        (kGridMaxTracks - trackSizes.size()) / autoRepeatTrackListLength;
+  }
+
   return repetitions * autoRepeatTrackListLength;
 }