Gracefully handle zero duration curves in CCActiveAnimation

cc/test/CCAnimationTestCommon.h

 // Copyright 2012 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 CCAnimationTestCommon_h
 #define CCAnimationTestCommon_h
 
 #include "CCActiveAnimation.h"
 #include "CCAnimationCurve.h"
 #include "CCLayerAnimationController.h"
 #include "IntSize.h"
 
 #include <wtf/OwnPtr.h>
 
 namespace cc {
 class CCLayerImpl;
 class LayerChromium;
 }
 
 namespace WebKitTests {
 
 class FakeFloatAnimationCurve : public cc::CCFloatAnimationCurve {
 public:
     FakeFloatAnimationCurve();
+    explicit FakeFloatAnimationCurve(double duration);
     virtual ~FakeFloatAnimationCurve();
 
     virtual double duration() const OVERRIDE;
     virtual float getValue(double now) const OVERRIDE;
     virtual PassOwnPtr<cc::CCAnimationCurve> clone() const OVERRIDE;
+
+private:
+    double m_duration;
 };
 
 class FakeTransformTransition : public cc::CCTransformAnimationCurve {
 public:
     FakeTransformTransition(double duration);
     virtual ~FakeTransformTransition();
 
     virtual double duration() const OVERRIDE;
     virtual WebKit::WebTransformationMatrix getValue(double time) const OVERRIDE;
 
@@ skipping 41 matching lines @@
 
 void addOpacityTransitionToLayer(cc::LayerChromium&, double duration, float startOpacity, float endOpacity, bool useTimingFunction);
 void addOpacityTransitionToLayer(cc::CCLayerImpl&, double duration, float startOpacity, float endOpacity, bool useTimingFunction);
 
 void addAnimatedTransformToLayer(cc::LayerChromium&, double duration, int deltaX, int deltaY);
 void addAnimatedTransformToLayer(cc::CCLayerImpl&, double duration, int deltaX, int deltaY);
 
 } // namespace WebKitTests
 
 #endif // CCAnimationTesctCommon_h