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..2c32814672aeab19d3ae31d0bb5c4b9a06d9b242 100644
--- a/Source/core/css/resolver/ScopedStyleResolver.cpp
+++ b/Source/core/css/resolver/ScopedStyleResolver.cpp
@@ -90,23 +90,38 @@ void ScopedStyleResolver::resetAuthorStyle()
     m_keyframesRuleMap.clear();
 }
 
-const StyleRuleKeyframes* ScopedStyleResolver::keyframeStylesForAnimation(const StringImpl* animationName)
+const StyleRuleKeyframes* ScopedStyleResolver::keyframeStylesForAnimation(const StringImpl* animationName) const
 {
     if (m_keyframesRuleMap.isEmpty())
         return 0;
 
-    KeyframesRuleMap::iterator it = m_keyframesRuleMap.find(animationName);
+    KeyframesRuleMap::const_iterator it = m_keyframesRuleMap.find(animationName);
     if (it == m_keyframesRuleMap.end())
         return 0;
 
     return it->value.get();
 }
 
+PassRefPtrWillBeRawPtr<StyleRuleKeyframes> ScopedStyleResolver::keyframeStylesForAnimation(const StringImpl* animationName)
+{
+    if (m_keyframesRuleMap.isEmpty())
+        return nullptr;
+
+    KeyframesRuleMap::iterator it = m_keyframesRuleMap.find(animationName);
+    if (it == m_keyframesRuleMap.end())
+        return nullptr;
+
+    return it->value;
+}
+
 void ScopedStyleResolver::addKeyframeStyle(PassRefPtrWillBeRawPtr<StyleRuleKeyframes> rule)
 {
     AtomicString s(rule->name());
+
+    rule->styleChanged();

[dstockwell, 2015/01/05 07:31:18]

I think on Friday we discussed that we need to call this in one more place: when
we're mutating a keyframe already added to a keyframes rule.

[shend, 2015/01/06 00:36:17]

Modifying the style of an existing keyframe seems to be handled by this (see
test), but setting the key text has to be separately handled.

[dstockwell, 2015/01/07 00:18:33]

Hmm, but how does that work?

[shend, 2015/01/08 05:05:29]

I'm not exactly sure, but if you follow the call tree back up, it looks like
this method is called every time a new StyleResolver is created
(StyleEngine::ensureResolver), and a new StyleResolver seems to be created every
time I change the style of a keyframe. Is this the expected behaviour?

[dstockwell, 2015/01/08 05:27:24]

Ahh, I see! I think I misunderstood the purpose of this method. I think this
means that any time the style sheet is mutated (and the style resolver cleared)
we will bump the counts on all keyframes. @shans, wdyt?

+
     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())