Move interpolated Length unit types out of InterpolableValue into NonInterpolableValue

Source/core/animation/InterpolationType.h

Index: Source/core/animation/InterpolationType.h
diff --git a/Source/core/animation/InterpolationType.h b/Source/core/animation/InterpolationType.h
index b500552f2cfffc982ad49dbae81d83b5c7a2c7ed..3568441e3cc019bc33b8bc6d8d89d2212881f79a 100644
--- a/Source/core/animation/InterpolationType.h
+++ b/Source/core/animation/InterpolationType.h
@@ -74,7 +74,7 @@ public:
 
     virtual void apply(const InterpolableValue&, const NonInterpolableValue*, StyleResolverState&) const = 0;
 
-    // Implement reference equality checking via pointer equality checking as these are singletons
+    // Implement reference equality checking via pointer equality checking as these are singletons.
     bool operator==(const InterpolationType& other) const { return this == &other; }
     bool operator!=(const InterpolationType& other) const { return this != &other; }