Avoid SVG viewport bug for CSS length animations that don't use viewport units

third_party/WebKit/Source/core/animation/LengthInterpolationFunctions.cpp

 // Copyright 2016 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 "core/animation/LengthInterpolationFunctions.h"
 
 #include "core/css/CSSPrimitiveValue.h"
 #include "core/css/CSSToLengthConversionData.h"
 #include "platform/CalculationValue.h"
 
@@ skipping 131 matching lines @@
 }
 
 Length LengthInterpolationFunctions::createLength(const InterpolableValue& interpolableValue, const NonInterpolableValue* nonInterpolableValue, const CSSToLengthConversionData& conversionData, ValueRange range)
 {
     const InterpolableList& interpolableList = toInterpolableList(interpolableValue);
     bool hasPercentage = CSSLengthNonInterpolableValue::hasPercentage(nonInterpolableValue);
     double pixels = 0;
     double percentage = 0;
     for (size_t i = 0; i < CSSPrimitiveValue::LengthUnitTypeCount; i++) {
         double value = toInterpolableNumber(*interpolableList.get(i)).value();
+        if (value == 0)
+            continue;
         if (i == CSSPrimitiveValue::UnitTypePercentage) {
             percentage = value;
         } else {
             CSSPrimitiveValue::UnitType type = CSSPrimitiveValue::lengthUnitTypeToUnitType(static_cast<CSSPrimitiveValue::LengthUnitType>(i));
             pixels += conversionData.zoomedComputedPixels(value, type);
         }
     }
 
     if (percentage != 0)
         hasPercentage = true;
     if (pixels != 0 && hasPercentage)
         return Length(CalculationValue::create(PixelsAndPercent(pixels, percentage), range));
     if (hasPercentage)
         return Length(clampToRange(percentage, range), Percent);
     return Length(CSSPrimitiveValue::clampToCSSLengthRange(clampToRange(pixels, range)), Fixed);
 }
 
 } // namespace blink