Web Animations: Support animation of SVG number attributes

Source/core/animation/NumberSVGInterpolation.cpp

Index: Source/core/animation/NumberSVGInterpolation.cpp
diff --git a/Source/core/animation/NumberSVGInterpolation.cpp b/Source/core/animation/NumberSVGInterpolation.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..ee46a45fdf0dfd9d158292da8028c062bb604307
--- /dev/null
+++ b/Source/core/animation/NumberSVGInterpolation.cpp
@@ -0,0 +1,18 @@
+// 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.
+
+#include "config.h"
+#include "core/animation/NumberSVGInterpolation.h"
+
+namespace blink {
+
+PassRefPtrWillBeRawPtr<SVGNumber> NumberSVGInterpolation::fromInterpolableValue(const InterpolableValue& value, SVGNumberNegativeValuesMode negativeValuesMode)
+{
+    double doubleValue = toInterpolableNumber(value).value();
+    if (negativeValuesMode == ForbidNegativeNumbers && doubleValue < 0)
+        doubleValue = 0;
+    return SVGNumber::create(doubleValue);
+}
+
+}