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..442699583675eb0ba20760d517e69dd6dad49ff6 100644
--- a/Source/core/css/resolver/ScopedStyleResolver.cpp
+++ b/Source/core/css/resolver/ScopedStyleResolver.cpp
@@ -90,23 +90,26 @@ void ScopedStyleResolver::resetAuthorStyle()
     m_keyframesRuleMap.clear();
 }
 
-const StyleRuleKeyframes* ScopedStyleResolver::keyframeStylesForAnimation(const StringImpl* animationName)
+PassRefPtrWillBeRawPtr<StyleRuleKeyframes> ScopedStyleResolver::keyframeStylesForAnimation(const StringImpl* animationName)
 {
     if (m_keyframesRuleMap.isEmpty())
-        return 0;
+        return nullptr;
 
     KeyframesRuleMap::iterator it = m_keyframesRuleMap.find(animationName);
     if (it == m_keyframesRuleMap.end())
-        return 0;
+        return nullptr;
 
-    return it->value.get();
+    return it->value;
 }
 
 void ScopedStyleResolver::addKeyframeStyle(PassRefPtrWillBeRawPtr<StyleRuleKeyframes> rule)
 {
     AtomicString s(rule->name());
+
+    rule->styleChanged();
+
     if (rule->isVendorPrefixed()) {
-        KeyframesRuleMap::iterator it = m_keyframesRuleMap.find(rule->name().impl());
+        KeyframesRuleMap::iterator it = m_keyframesRuleMap.find(s.impl());
         if (it == m_keyframesRuleMap.end())
             m_keyframesRuleMap.set(s.impl(), rule);
         else if (it->value->isVendorPrefixed())