WIP CSSPropertyParserHelpers::ConsumeCommaSeparatedList template

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CSSPropertyParserHelpers_h
 #define CSSPropertyParserHelpers_h
 
 #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
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class CSSParserContext;
 class CSSStringValue;
 class CSSURIValue;
@@ skipping 93 matching lines @@
 }
 
 template <CSSValueID... names>
 CSSIdentifierValue* ConsumeIdent(CSSParserTokenRange& range) {
   if (range.Peek().GetType() != kIdentToken ||
       !IdentMatches<names...>(range.Peek().Id()))
     return nullptr;
   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
 
 #endif  // CSSPropertyParserHelpers_h