Oilpan: build fix after r172864.

Source/core/animation/EffectInputTest.cpp

Index: Source/core/animation/EffectInputTest.cpp
diff --git a/Source/core/animation/EffectInputTest.cpp b/Source/core/animation/EffectInputTest.cpp
index f3013287dd157178ff635949c5739553880fb27a..65561dc46340ab4b20c21bf4d72ee45c7b0946b6 100644
--- a/Source/core/animation/EffectInputTest.cpp
+++ b/Source/core/animation/EffectInputTest.cpp
@@ -117,7 +117,7 @@ TEST_F(AnimationEffectInputTest, Invalid)
     jsKeyframes.append(Dictionary(keyframe2, m_isolate));
     jsKeyframes.append(Dictionary(keyframe3, m_isolate));
 
-    RefPtrWillBeRawPtr<AnimationEffect> animationEffect = EffectInput::convert(element.get(), jsKeyframes, exceptionState, true);
+    RefPtrWillBeRawPtr<AnimationEffect> animationEffect ALLOW_UNUSED = EffectInput::convert(element.get(), jsKeyframes, exceptionState, true);
     EXPECT_TRUE(exceptionState.hadException());
     EXPECT_EQ(InvalidModificationError, exceptionState.code());
 }