Update animation when changes in animation keyframes are detected.

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 1aeeff988d75d22090289b1c540d30372d11e158..3c318872f100726153d1ceb3dd11acd344799eb3 100644
--- a/Source/core/css/CSSKeyframeRule.cpp
+++ b/Source/core/css/CSSKeyframeRule.cpp
@@ -28,6 +28,7 @@
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/css/CSSKeyframesRule.h"
+#include "core/css/CSSStyleSheet.h"
 #include "core/css/PropertySetCSSStyleDeclaration.h"
 #include "core/dom/ExceptionCode.h"
 
@@ -52,6 +53,9 @@ void CSSKeyframeRule::setKeyText(const String& keyText, ExceptionState& exceptio
 {
     if (!m_keyframe->setKeyText(keyText))
         exceptionState.throwDOMException(SyntaxError, "The key '" + keyText + "' is invalid and cannot be parsed");
+
+    CSSKeyframesRule* parent = toCSSKeyframesRule(parentRule());
+    parent->m_keyframesRule->styleChanged();
 }
 
 CSSStyleDeclaration* CSSKeyframeRule::style() const