Web Animations CSS: Support animation of {text,box,-webkit-box}-shadow and fix blur clamping

Source/core/animation/AnimatableShadow.cpp

Index: Source/core/animation/AnimatableShadow.cpp
diff --git a/Source/core/animation/AnimatableSVGLength.cpp b/Source/core/animation/AnimatableShadow.cpp
similarity index 64%
copy from Source/core/animation/AnimatableSVGLength.cpp
copy to Source/core/animation/AnimatableShadow.cpp
index bbf13e3f2f3f636f7e8a87377c59edf60f6fa64f..4d1a847f319b7de819d8fe25a3f461aac6b45a53 100644
--- a/Source/core/animation/AnimatableSVGLength.cpp
+++ b/Source/core/animation/AnimatableShadow.cpp
@@ -29,26 +29,27 @@
  */
 
 #include "config.h"
-#include "core/animation/AnimatableSVGLength.h"
-
-#include "platform/FloatConversion.h"
+#include "core/animation/AnimatableShadow.h"
 
 namespace WebCore {
 
-PassRefPtr<AnimatableValue> AnimatableSVGLength::interpolateTo(const AnimatableValue* value, double fraction) const
+PassRefPtr<AnimatableValue> AnimatableShadow::interpolateTo(const AnimatableValue* value, double fraction) const
 {
-    return create(toAnimatableSVGLength(value)->toSVGLength().blend(m_length, narrowPrecisionToFloat(fraction)));
+    const AnimatableShadow* shadowList = toAnimatableShadow(value);
+    return AnimatableShadow::create(ShadowList::blend(m_shadowList.get(), shadowList->m_shadowList.get(), fraction));
 }
 
-PassRefPtr<AnimatableValue> AnimatableSVGLength::addWith(const AnimatableValue* value) const
+PassRefPtr<AnimatableValue> AnimatableShadow::addWith(const AnimatableValue* value) const
 {
-    RELEASE_ASSERT_WITH_MESSAGE(false, "Web Animations not yet implemented: AnimatableSVGLength::addWith()");
-    return 0;
+    // FIXME: The spec doesn't specify anything for shadow in particular, but
+    // the default behaviour is probably not what one would expect.
+    return AnimatableValue::defaultAddWith(this, value);
 }
 
-bool AnimatableSVGLength::equalTo(const AnimatableValue* value) const
+bool AnimatableShadow::equalTo(const AnimatableValue* value) const
 {
-    return m_length == toAnimatableSVGLength(value)->m_length;
+    const ShadowList* shadowList = toAnimatableShadow(value)->m_shadowList.get();
+    return m_shadowList == shadowList || (m_shadowList && shadowList && *m_shadowList == *shadowList);
 }
 
 } // namespace WebCore