Add a virtual destructor for InterpolationType

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

 // 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 InterpolationType_h
 #define InterpolationType_h
 
 #include "core/animation/InterpolationValue.h"
 #include "core/animation/Keyframe.h"
 #include "core/animation/PairwiseInterpolationValue.h"
@@ skipping 13 matching lines @@
 // - Convert PropertySpecificKeyframe values to (Pairwise)?InterpolationValues:
 // maybeConvertPairwise() and maybeConvertSingle()
 // - Convert the target Element's property value to an InterpolationValue:
 // maybeConvertUnderlyingValue()
 // - Apply an InterpolationValue to a target Element's property: apply().
 class InterpolationType {
   USING_FAST_MALLOC(InterpolationType);
   WTF_MAKE_NONCOPYABLE(InterpolationType);
 
  public:
+  virtual ~InterpolationType() {}
+
   PropertyHandle getProperty() const { return m_property; }
 
   // ConversionCheckers are returned from calls to maybeConvertPairwise() and
   // maybeConvertSingle() to enable the caller to check whether the result is
   // still valid given changes in the InterpolationEnvironment and underlying
   // InterpolationValue.
   class ConversionChecker {
     USING_FAST_MALLOC(ConversionChecker);
     WTF_MAKE_NONCOPYABLE(ConversionChecker);
 
@@ skipping 71 matching lines @@
 
  protected:
   InterpolationType(PropertyHandle property) : m_property(property) {}
 
   const PropertyHandle m_property;
 };
 
 }  // namespace blink
 
 #endif  // InterpolationType_h