ASSERTION FAILED: !m_overflow

third_party/WebKit/Source/core/layout/line/InlineBox.h

Index: third_party/WebKit/Source/core/layout/line/InlineBox.h
diff --git a/third_party/WebKit/Source/core/layout/line/InlineBox.h b/third_party/WebKit/Source/core/layout/line/InlineBox.h
index dedadf41a79901c3a6e0a5fbc0c7bcdc163b3345..05a5c9a029ed415016a8755944df2662c9e4ead1 100644
--- a/third_party/WebKit/Source/core/layout/line/InlineBox.h
+++ b/third_party/WebKit/Source/core/layout/line/InlineBox.h
@@ -351,6 +351,13 @@ public:
         ADD_BOOLEAN_BITFIELD(endsWithBreak, EndsWithBreak); // Whether the line ends with a <br>.
         // shared between RootInlineBox and InlineTextBox
         ADD_BOOLEAN_BITFIELD(hasSelectedChildrenOrCanHaveLeadingExpansion, HasSelectedChildrenOrCanHaveLeadingExpansion);
+
+        // This boolean will never be set if there is potential for overflow,
+        // but it will be eagerly cleared in the opposite case. As such, it's
+        // a conservative tracking of the absence of overflow.
+        //
+        // For whether we have overflow, callers should use m_overflow on
+        // InlineFlowBox.
         ADD_BOOLEAN_BITFIELD(knownToHaveNoOverflow, KnownToHaveNoOverflow);
         ADD_BOOLEAN_BITFIELD(hasEllipsisBoxOrHyphen, HasEllipsisBoxOrHyphen);
         // for InlineTextBox