Web Animations: Add SVGNumberListInterpolationType

third_party/WebKit/Source/core/animation/UnderlyingLengthChecker.h

Index: third_party/WebKit/Source/core/animation/UnderlyingLengthChecker.h
diff --git a/third_party/WebKit/Source/core/animation/UnderlyingLengthChecker.h b/third_party/WebKit/Source/core/animation/UnderlyingLengthChecker.h
new file mode 100644
index 0000000000000000000000000000000000000000..2ded6d49df1ccc2aef521acfcfa8c8d21b241b4a
--- /dev/null
+++ b/third_party/WebKit/Source/core/animation/UnderlyingLengthChecker.h
@@ -0,0 +1,44 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UnderlyingLengthChecker_h
+#define UnderlyingLengthChecker_h
+
+#include "core/animation/InterpolableValue.h"
+#include "core/animation/InterpolationType.h"
+#include "core/animation/UnderlyingValue.h"
+
+namespace blink {
+
+class UnderlyingLengthChecker : public InterpolationType::ConversionChecker {
+public:
+    static PassOwnPtr<UnderlyingLengthChecker> create(const InterpolationType& type, size_t underlyingLength)
+    {
+        return adoptPtr(new UnderlyingLengthChecker(type, underlyingLength));
+    }
+
+    static size_t getUnderlyingLength(const UnderlyingValue& underlyingValue)
+    {
+        if (!underlyingValue)
+            return 0;
+        return toInterpolableList(underlyingValue->interpolableValue()).length();
+    }
+
+    bool isValid(const InterpolationEnvironment&, const UnderlyingValue& underlyingValue) const final
+    {
+        return m_underlyingLength == getUnderlyingLength(underlyingValue);
+    }
+
+private:
+    UnderlyingLengthChecker(const InterpolationType& type, size_t underlyingLength)
+        : ConversionChecker(type)
+        , m_underlyingLength(underlyingLength)
+    {}
+
+    size_t m_underlyingLength;
+};
+
+} // namespace blink
+
+#endif // UnderlyingLengthChecker_h