[oilpan] Rename visit to mark.

Source/core/css/CSSFontSelector.cpp

Index: Source/core/css/CSSFontSelector.cpp
diff --git a/Source/core/css/CSSFontSelector.cpp b/Source/core/css/CSSFontSelector.cpp
index 7340f0e57ff13f3825f458066b7f1a2344faee21..902316438ac68f01476521af22ae33061d64c628 100644
--- a/Source/core/css/CSSFontSelector.cpp
+++ b/Source/core/css/CSSFontSelector.cpp
@@ -628,10 +628,7 @@ void CSSFontSelector::beginLoadTimerFired(Timer<WebCore::CSSFontSelector>*)
 
 void CSSFontSelector::trace(Visitor* visitor)
 {
-    // FIXME(oilpan): visiting m_document creates a cycle through a persistent handle because document owns StyleResolver
-    // which hold CSSFontSelector via persistent handle. Once StyleResolver is moved to the heap we should start visiting
-    // m_document again.
-    // visitor->trace(m_document);
+    visitor->trace(m_document);
     visitor->trace(m_fontFaces);
     visitor->trace(m_locallyInstalledFontFaces);
     visitor->trace(m_fonts);