Devtools Animations: Basic animation inspection & control in Styles pane

Source/core/animation/StringKeyframe.h

Index: Source/core/animation/StringKeyframe.h
diff --git a/Source/core/animation/StringKeyframe.h b/Source/core/animation/StringKeyframe.h
index a55a501006e22fe96321abd7fefa5e964a0703da..3755e1f5fe5f6e8ba149fd1efc12af44e54e8e53 100644
--- a/Source/core/animation/StringKeyframe.h
+++ b/Source/core/animation/StringKeyframe.h
@@ -13,6 +13,8 @@ namespace blink {
 class StyleSheetContents;
 
 class StringKeyframe : public Keyframe {
+friend class InspectorCSSAgent;
+
 public:
     static PassRefPtrWillBeRawPtr<StringKeyframe> create()
     {
@@ -54,6 +56,9 @@ public:
         mutable RefPtrWillBeMember<AnimatableValue> m_animatableValueCache;
     };
 
+protected:
+    MutableStylePropertySet* propertySet () const { return m_propertySet.get(); }
+
 private:
     StringKeyframe()
         : m_propertySet(MutableStylePropertySet::create())