Make CSSParserContext be garbage collected.

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

Index: third_party/WebKit/Source/core/css/FontFace.cpp
diff --git a/third_party/WebKit/Source/core/css/FontFace.cpp b/third_party/WebKit/Source/core/css/FontFace.cpp
index f199686ac84782f0a69d487cd8a31fb09e8d7d5d..a76bcf017701e24bce5e21a5811d2ddd26cece8e 100644
--- a/third_party/WebKit/Source/core/css/FontFace.cpp
+++ b/third_party/WebKit/Source/core/css/FontFace.cpp
@@ -66,7 +66,8 @@ namespace blink {
 static const CSSValue* parseCSSValue(const Document* document,
                                      const String& value,
                                      CSSPropertyID propertyID) {
-  CSSParserContext context(*document, UseCounter::getFrom(document));
+  CSSParserContext* context = new CSSParserContext(*document);
+  context->setUseCounter(UseCounter::getFrom(document));

[haraken, 2017/01/12 04:51:13]

It looks not really nice that we have to create CSSParserContext and call
setUserCounter separately.

Once your refactoring is done, what will it look like in the end?

[Bret, 2017/01/13 02:15:28]

Yes, I'm wasn't entirely happy with this. I changed around the construction
interface when I made all the factories so now it doesn't need to be a separate
statement.

   return CSSParser::parseFontFaceDescriptor(propertyID, value, context);
 }