Implement all shorthand property.

Source/core/css/StylePropertyShorthandCustom.cpp

Index: Source/core/css/StylePropertyShorthandCustom.cpp
diff --git a/Source/core/css/StylePropertyShorthandCustom.cpp b/Source/core/css/StylePropertyShorthandCustom.cpp
index b157746c8b99736ec302206f380d2deb93dc3e79..d561e94a435344f30fa436e5cb3cdee9a13600f0 100644
--- a/Source/core/css/StylePropertyShorthandCustom.cpp
+++ b/Source/core/css/StylePropertyShorthandCustom.cpp
@@ -113,6 +113,22 @@ bool isExpandedShorthand(CSSPropertyID id)
     return shorthandForProperty(id).length();
 }
 
+bool isExpandedShorthandForAll(CSSPropertyID propertyId)
+{
+    // FIXME: isExpandedShorthand says "font" is not an expanded shorthand,
+    // but font is expanded to font-family, font-size, and so on.
+    // StylePropertySerializer::asText should not generate css text like
+    // "font: initial; font-family: initial;...". To avoid this, we need to
+    // treat "font" as an expanded shorthand.
+    // And while applying "all" property, we cannot apply "font" property
+    // directly. This causes ASSERT crash, because StyleBuilder assume that
+    // all given properties are not expanded shorthands.
+    // "marker" has the same issue.
+    if (propertyId == CSSPropertyMarker || propertyId == CSSPropertyFont)
+        return true;
+    return shorthandForProperty(propertyId).length();
+}
+
 unsigned indexOfShorthandForLonghand(CSSPropertyID shorthandID, const Vector<StylePropertyShorthand, 4>& shorthands)
 {
     for (unsigned i = 0; i < shorthands.size(); ++i) {