Rename cleanup in comments in css/ directory.

third_party/WebKit/Source/core/css/CSSFontSelector.cpp

Index: third_party/WebKit/Source/core/css/CSSFontSelector.cpp
diff --git a/third_party/WebKit/Source/core/css/CSSFontSelector.cpp b/third_party/WebKit/Source/core/css/CSSFontSelector.cpp
index 9bfc43bfb59a7b4e6975cadaa23aac900887e235..d01e9180f8af4b6948a7cb026fa25119a607bca6 100644
--- a/third_party/WebKit/Source/core/css/CSSFontSelector.cpp
+++ b/third_party/WebKit/Source/core/css/CSSFontSelector.cpp
@@ -47,7 +47,7 @@ CSSFontSelector::CSSFontSelector(Document* document)
       generic_font_family_settings_(
           document->GetFrame()->GetSettings()->GetGenericFontFamilySettings()) {
   // FIXME: An old comment used to say there was no need to hold a reference to
-  // m_document because "we are guaranteed to be destroyed before the document".
+  // document_ because "we are guaranteed to be destroyed before the document".
   // But there does not seem to be any such guarantee.
   DCHECK(document_);
   DCHECK(document_->GetFrame());