WIP CSSPropertyParserHelpers::ConsumeCommaSeparatedList template

third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.h

Index: third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.h
diff --git a/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.h b/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.h
index 9e56d2c0c7136ba910f39fb2babe458030ecda38..a542e3eb524b5348814438fb7e385fd07e1883b6 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.h
+++ b/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.h
@@ -8,6 +8,7 @@
 #include "core/css/CSSCustomIdentValue.h"
 #include "core/css/CSSIdentifierValue.h"
 #include "core/css/CSSPrimitiveValue.h"
+#include "core/css/CSSValueList.h"
 #include "core/css/parser/CSSParserMode.h"
 #include "core/css/parser/CSSParserTokenRange.h"
 #include "platform/Length.h"  // For ValueRange
@@ -121,6 +122,22 @@ CSSIdentifierValue* ConsumeIdent(CSSParserTokenRange& range) {
   return CSSIdentifierValue::Create(range.ConsumeIncludingWhitespace().Id());
 }
 
+// TODO(bugsnash): add comment about callback requirements
+template <typename callback, typename... Args>
+CSSValueList* ConsumeCommaSeparatedList(CSSParserTokenRange& range,
+                                        callback f,
+                                        Args... args) {
+  CSSValueList* list = CSSValueList::CreateCommaSeparated();
+  do {
+    CSSValue* value = f(range, args...);
+    if (!value)
+      return nullptr;
+    list->Append(*value);
+  } while (ConsumeCommaIncludingWhitespace(range));
+  DCHECK(list->length());
+  return list;
+}
+
 }  // namespace CSSPropertyParserHelpers
 
 }  // namespace blink