Web Animations: Support animation of SVG number attributes

Source/core/animation/NumberSVGInterpolation.cpp

+// 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<NumberSVGInterpolation> NumberSVGInterpolation::create(SVGPropertyBase* start, SVGPropertyBase* end, PassRefPtrWillBeRawPtr<SVGAnimatedPropertyBase> attribute)
+{
+    SVGNumberNegativeValuesMode negativeValuesMode = &attribute->attributeName() == &SVGNames::pathLengthAttr ? ForbidNegativeNumbers : AllowNegativeNumbers;

[alancutter (OOO until 2018), 2015/04/20 07:39:40]

It would be more consistent to have this property specific logic in
StringKeyframe.

[Eric Willigers, 2015/04/21 00:51:16]

Done. Also done for IntegerOptionalInteger.

+    return adoptRefWillBeNoop(new NumberSVGInterpolation(toInterpolableValue(start), toInterpolableValue(end), attribute, negativeValuesMode));
+}
+
+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);
+}
+
+}