[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..fc729252b1215b8b1d02fc93bfeccff8258c2c23 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
@@ -2042,6 +2042,12 @@ size_t LayoutGrid::computeAutoRepeatTracksCount(
   if (needsToFulfillMinimumSize)
     ++repetitions;
 
+  // Clamp the number of repetitions so we don't end up with too many tracks

[Manuel Rego, 2017/01/27 09:05:57]

Nit: Missing dot after comment.

+  if (repetitions > kGridMaxTracks) {
+    repetitions =
+        (kGridMaxTracks - trackSizes.size()) / autoRepeatTrackListLength;

[eae, 2017/01/26 17:07:23]

I know we early return if autoRepeatTrackListLength is zero but that is over
three hundred lines away and might change. Would you mind adding a
DCHECK(autoRepeatTrackListLength) here?

+  }
+
   return repetitions * autoRepeatTrackListLength;
 }