Harmonize FilterEffect::mapRect and mapPaintRect

third_party/WebKit/Source/platform/graphics/filters/FEConvolveMatrix.cpp

Index: third_party/WebKit/Source/platform/graphics/filters/FEConvolveMatrix.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/filters/FEConvolveMatrix.cpp b/third_party/WebKit/Source/platform/graphics/filters/FEConvolveMatrix.cpp
index ece3a8df1e077e65d2f04e5087fa1f14d868710d..fa9f9e99e5b62718abcdf835fc088201e9ca337a 100644
--- a/third_party/WebKit/Source/platform/graphics/filters/FEConvolveMatrix.cpp
+++ b/third_party/WebKit/Source/platform/graphics/filters/FEConvolveMatrix.cpp
@@ -55,13 +55,13 @@ FEConvolveMatrix* FEConvolveMatrix::create(Filter* filter, const IntSize& kernel
         preserveAlpha, kernelMatrix);
 }
 
-FloatRect FEConvolveMatrix::mapPaintRect(const FloatRect& rect, bool forward) const
+FloatRect FEConvolveMatrix::mapEffect(const FloatRect& rect) const
 {
+    if (!parametersValid())
+        return rect;
     FloatRect result = rect;
-    if (parametersValid()) {
-        result.moveBy(forward ? -m_targetOffset : m_targetOffset - m_kernelSize);
-        result.expand(FloatSize(m_kernelSize));
-    }
+    result.moveBy(-m_targetOffset);
+    result.expand(FloatSize(m_kernelSize));
     return result;
 }