Avoid reparsing keyframe selectors

Source/core/css/CSSParser.cpp

Index: Source/core/css/CSSParser.cpp
diff --git a/Source/core/css/CSSParser.cpp b/Source/core/css/CSSParser.cpp
index d5986b7312f64ce49759eb68bd6df02d68bff85b..a0b34e4a77db9a64d17bf905aeeddb73f84c311d 100644
--- a/Source/core/css/CSSParser.cpp
+++ b/Source/core/css/CSSParser.cpp
@@ -11021,8 +11021,15 @@ StyleRuleKeyframes* CSSParser::createKeyframesRule(const String& name, PassOwnPt
     OwnPtr<Vector<RefPtr<StyleKeyframe> > > keyframes = popKeyframes;
     m_allowImportRules = m_allowNamespaceDeclarations = false;
     RefPtr<StyleRuleKeyframes> rule = StyleRuleKeyframes::create();
-    for (size_t i = 0; i < keyframes->size(); ++i)
-        rule->parserAppendKeyframe(keyframes->at(i));
+    for (size_t i = 0; i < keyframes->size(); ++i) {
+        RefPtr<StyleKeyframe> keyframe = keyframes->at(i);
+        if (keyframe->isValid()) {
+            rule->parserAppendKeyframe(keyframe);
+            continue;
+        }
+        return 0;
+    }
+
     rule->setName(name);
     StyleRuleKeyframes* rulePtr = rule.get();
     m_parsedRules.append(rule.release());
@@ -11276,18 +11283,20 @@ void CSSParser::deleteFontFaceOnlyValues()
 
 StyleKeyframe* CSSParser::createKeyframe(CSSParserValueList* keys)
 {
-    // Create a key string from the passed keys
-    StringBuilder keyString;
-    for (unsigned i = 0; i < keys->size(); ++i) {
-        float key = static_cast<float>(keys->valueAt(i)->fValue);
-        if (i != 0)
-            keyString.append(',');
-        keyString.append(String::number(key));
-        keyString.append('%');
+    Vector<float> keyframeKeys;
+    unsigned keyCount = keys->size();
+    for (unsigned i = 0; i < keyCount; ++i) {
+        CSSParserValue* value = keys->valueAt(i);
+        if (value && value->unit == CSSPrimitiveValue::CSS_NUMBER) {
+            keyframeKeys.append(static_cast<float>(value->fValue / 100));
+            continue;
+        }
+        keyframeKeys.clear();
+        break;
     }
 
     RefPtr<StyleKeyframe> keyframe = StyleKeyframe::create();
-    keyframe->setKeyText(keyString.toString());
+    keyframe->setKeys(keyframeKeys);
     keyframe->setProperties(createStylePropertySet());
 
     clearProperties();