Fix number handling in accumulatePixelsAndPercent.

Source/core/css/parser/CSSPropertyParser.cpp

Index: Source/core/css/parser/CSSPropertyParser.cpp
diff --git a/Source/core/css/parser/CSSPropertyParser.cpp b/Source/core/css/parser/CSSPropertyParser.cpp
index 3e50cab7bcf86ea4fc864aea921a173b5e2021de..c2b46a7a18b31b8dbcf0d0c46b5e277b38a53699 100644
--- a/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/Source/core/css/parser/CSSPropertyParser.cpp
@@ -4684,6 +4684,12 @@ bool CSSPropertyParser::parseLineHeight(bool important)
         validPrimitive = true;
     else
         validPrimitive = (!id && validUnit(value, FNumber | FLength | FPercent | FNonNeg));
+    // The line-height property can accept both percents and numbers but additive opertaions are
+    // not permitted on them in calc() expressions.
+    if (m_parsedCalculation && m_parsedCalculation->category() == CalcPercentNumber) {
+        validPrimitive = false;
+        m_parsedCalculation.release();
+    }
     if (validPrimitive && (!m_valueList->next() || inShorthand()))
         addProperty(CSSPropertyLineHeight, parseValidPrimitive(id, value), important);
     return validPrimitive;