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..de5115ae9d5decdd33026d78ec477923173fbc6b 100644
--- a/third_party/WebKit/Source/core/layout/line/InlineBox.h
+++ b/third_party/WebKit/Source/core/layout/line/InlineBox.h
@@ -351,6 +351,15 @@ 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 tracks whether we know that this box has no overflow.

[leviw_travelin_and_unemployed, 2015/11/13 00:40:33]

Nit: I wouldn't even bother with this first line now that the rest of your
comment does a good job or wrapping up what this means.

[Julien - ping for review, 2015/11/13 02:08:26]

Fair, removed.

+        //
+        // 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