Avoid reparsing keyframe selectors

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 12f8ec3596c63d7ff5d27ffefc0a57dea8db4f4f..103f6d65d99e99f466b58d130c0f8712d54efd0b 100644
--- a/Source/core/css/CSSKeyframeRule.cpp
+++ b/Source/core/css/CSSKeyframeRule.cpp
@@ -53,6 +53,39 @@ void StyleKeyframe::setProperties(PassRefPtr<StylePropertySet> properties)
     m_properties = properties;
 }
 
+String StyleKeyframe::keyText() const
+{
+    size_t keyCount = m_keys.size();
+    if (m_keyText.isEmpty() && keyCount > 0) {
+        StringBuilder keyString;
+        for (size_t i = 0; i < keyCount; ++i) {
+            float key = m_keys[i];
+            if (i)
+                keyString.append(',');
+            keyString.append(String::number(key * 100));
+            keyString.append('%');
+        }
+        m_keyText = keyString.toString();
+    }
+    return m_keyText;
+}
+
+void StyleKeyframe::setKeyText(const String& s)
+{
+    parseKeyString(s, m_keys);
+
+    if (m_keys.size())
+        m_keyText = s;
+    else
+        m_keyText = String();
+}
+
+void StyleKeyframe::setKeys(const Vector<float>& keys)
+{
+    m_keyText = String();
+    m_keys = keys;
+}
+
 /* static */
 void StyleKeyframe::parseKeyString(const String& s, Vector<float>& keys)
 {
@@ -71,13 +104,14 @@ void StyleKeyframe::parseKeyString(const String& s, Vector<float>& keys)
             key = 1;
         else if (cur.endsWith('%')) {
             float k = cur.substring(0, cur.length() - 1).toFloat();
-            if (k >= 0 && k <= 100)
+            if (k >= 0 && k <= 100) {
                 key = k / 100;
+            } else {
+                keys.clear();
+                return;
+            }
         }
-        if (key < 0) {
-            keys.clear();
-            return;
-        }
+
         keys.append(key);
     }
 }
@@ -99,7 +133,7 @@ void StyleKeyframe::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
 {
     MemoryClassInfo info(memoryObjectInfo, this, WebCoreMemoryTypes::CSS);
     info.addMember(m_properties, "properties");
-    info.addMember(m_key, "key");
+    info.addMember(m_keyText, "keyText");
 }
 
 CSSKeyframeRule::CSSKeyframeRule(StyleKeyframe* keyframe, CSSKeyframesRule* parent)