Web Animations: define distance for AnimatableColor

Source/core/animation/AnimatableValue.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/animation/AnimatableValue.h"
 #include "core/animation/AnimatableNeutral.h"
 #include "wtf/StdLibExtras.h"
 #include <algorithm>
 
+namespace {
+
+const double defaultDistance = 1;
+
+} // namespace
+
 namespace WebCore {
 
 const AnimatableValue* AnimatableValue::neutralValue()
 {
     DEFINE_STATIC_REF(AnimatableNeutral, neutralSentinelValue, (AnimatableNeutral::create()));
     return neutralSentinelValue;
 }
 
 PassRefPtr<AnimatableValue> AnimatableValue::interpolate(const AnimatableValue* left, const AnimatableValue* right, double fraction)
 {
@@ skipping 22 matching lines @@
         return left->addWith(right);
 
     return defaultAddWith(left, right);
 }
 
 PassRefPtr<AnimatableValue> AnimatableValue::addWith(const AnimatableValue* value) const
 {
     return defaultAddWith(this, value);
 }
 
+double AnimatableValue::distance(const AnimatableValue* left, const AnimatableValue* right)
+{
+    ASSERT(left);
+    ASSERT(right);
+
+    if (left->isSameType(right))
+        return left->distanceTo(right);
+
+    return defaultDistance;
+}
+
+double AnimatableValue::distanceTo(const AnimatableValue*) const
+{
+    return defaultDistance;
+}
+
 } // namespace WebCore