Revert of Revert of Split out CSSParser public API

Source/core/css/CSSKeyframeRule.cpp

Index: Source/core/css/CSSKeyframeRule.cpp
diff --git a/Source/core/css/CSSKeyframeRule.cpp b/Source/core/css/CSSKeyframeRule.cpp
index 1696ef4c9636351c881282298c3adac07c8013a0..6861388cc0d92bc099748825b3c9e95f99edd471 100644
--- a/Source/core/css/CSSKeyframeRule.cpp
+++ b/Source/core/css/CSSKeyframeRule.cpp
@@ -27,9 +27,9 @@
 #include "core/css/CSSKeyframeRule.h"
 
 #include "core/css/CSSKeyframesRule.h"
-#include "core/css/parser/BisonCSSParser.h"
 #include "core/css/PropertySetCSSStyleDeclaration.h"
 #include "core/css/StylePropertySet.h"
+#include "core/css/parser/CSSParser.h"
 #include "core/frame/UseCounter.h"
 #include "wtf/text/StringBuilder.h"
 
@@ -77,7 +77,7 @@
         // Keys can only be cleared by setting the key text from JavaScript
         // and this can never be null.
         ASSERT(!m_keyText.isNull());
-        m_keys = BisonCSSParser(strictCSSParserContext()).parseKeyframeKeyList(m_keyText);
+        m_keys = CSSParser::parseKeyframeKeyList(m_keyText);
     }
     // If an invalid key string was set, m_keys may be empty.
     ASSERT(m_keys);