Avoid reparsing keyframe selectors

Source/core/css/CSSParser.cpp

 /*
  * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
@@ skipping 11415 matching lines @@
         if (property.id() == CSSPropertyFontVariant && property.value()->isValueList()) {
             m_parsedProperties.remove(i);
             continue;
         }
         ++i;
     }
 }
 
 StyleKeyframe* CSSParser::createKeyframe(CSSParserValueList* keys)
 {
-    // Create a key string from the passed keys
-    StringBuilder keyString;
-    for (unsigned i = 0; i < keys->size(); ++i) {
+    Vector<float> keyframeKeys;
+    size_t keyCount = keys->size();
+    for (size_t i = 0; i < keyCount; ++i) {
         ASSERT(keys->valueAt(i)->unit == CSSPrimitiveValue::CSS_NUMBER);
         float key = static_cast<float>(keys->valueAt(i)->fValue);
         if (key < 0 || key > 100) {
             // As per http://www.w3.org/TR/css3-animations/#keyframes,
             // "If a keyframe selector specifies negative percentage values
             // or values higher than 100%, then the keyframe will be ignored."
             clearProperties();
             return 0;
         }
-        if (i != 0)
-            keyString.append(',');
-        keyString.append(String::number(key));
-        keyString.append('%');
+
+        keyframeKeys.append(key / 100);
     }
 
     RefPtr<StyleKeyframe> keyframe = StyleKeyframe::create();
-    keyframe->setKeyText(keyString.toString());
+    keyframe->setKeys(keyframeKeys);
     keyframe->setProperties(createStylePropertySet());
 
     clearProperties();
 
     StyleKeyframe* keyframePtr = keyframe.get();
     m_parsedKeyframes.append(keyframe.release());
     return keyframePtr;
 }
 
 void CSSParser::invalidBlockHit()
@@ skipping 412 matching lines @@
 {
     // The tokenizer checks for the construct of an+b.
     // However, since the {ident} rule precedes the {nth} rule, some of those
     // tokens are identified as string literal. Furthermore we need to accept
     // "odd" and "even" which does not match to an+b.
     return equalIgnoringCase(token, "odd") || equalIgnoringCase(token, "even")
         || equalIgnoringCase(token, "n") || equalIgnoringCase(token, "-n");
 }
 
 }