Update animation when changes in animation keyframes are detected.

Source/core/css/resolver/ScopedStyleResolver.cpp

Index: Source/core/css/resolver/ScopedStyleResolver.cpp
diff --git a/Source/core/css/resolver/ScopedStyleResolver.cpp b/Source/core/css/resolver/ScopedStyleResolver.cpp
index e3ccf263ce89cf6f8297b15c27800358541f6a8d..8adb35585c74f7414d6988012e2e73e93d6f54b7 100644
--- a/Source/core/css/resolver/ScopedStyleResolver.cpp
+++ b/Source/core/css/resolver/ScopedStyleResolver.cpp
@@ -105,8 +105,12 @@ const StyleRuleKeyframes* ScopedStyleResolver::keyframeStylesForAnimation(const
 void ScopedStyleResolver::addKeyframeStyle(PassRefPtrWillBeRawPtr<StyleRuleKeyframes> rule)
 {
     AtomicString s(rule->name());
+
+    KeyframesRuleMap::iterator it = m_keyframesRuleMap.find(s.impl());
+    if (it == m_keyframesRuleMap.end() || !(*rule == *it->value))
+        rule->styleChanged();
+
     if (rule->isVendorPrefixed()) {
-        KeyframesRuleMap::iterator it = m_keyframesRuleMap.find(rule->name().impl());
         if (it == m_keyframesRuleMap.end())
             m_keyframesRuleMap.set(s.impl(), rule);
         else if (it->value->isVendorPrefixed())