Some small cleanups for image filter code.

src/effects/SkBlurImageFilter.cpp

Index: src/effects/SkBlurImageFilter.cpp
diff --git a/src/effects/SkBlurImageFilter.cpp b/src/effects/SkBlurImageFilter.cpp
index 63990abc22d0e0faca11bb7e23c9bcec4426bb8b..00064d4668e664b5b95246671e64041b9d9f2e8a 100644
--- a/src/effects/SkBlurImageFilter.cpp
+++ b/src/effects/SkBlurImageFilter.cpp
@@ -169,8 +169,8 @@ bool SkBlurImageFilter::onFilterImage(Proxy* proxy,
         return false;
     }
 
-    SkVector sigma, localSigma = SkVector::Make(fSigma.width(), fSigma.height());
-    ctx.ctm().mapVectors(&sigma, &localSigma, 1);
+    SkVector sigma = SkVector::Make(fSigma.width(), fSigma.height());
+    ctx.ctm().mapVectors(&sigma, 1);
     sigma.fX = SkMinScalar(sigma.fX, MAX_SIGMA);
     sigma.fY = SkMinScalar(sigma.fY, MAX_SIGMA);
 
@@ -249,8 +249,8 @@ bool SkBlurImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
     if (getInput(0) && !getInput(0)->filterBounds(src, ctm, &bounds)) {
         return false;
     }
-    SkVector sigma, localSigma = SkVector::Make(fSigma.width(), fSigma.height());
-    ctm.mapVectors(&sigma, &localSigma, 1);
+    SkVector sigma = SkVector::Make(fSigma.width(), fSigma.height());
+    ctm.mapVectors(&sigma, 1);
     bounds.outset(SkScalarCeilToInt(SkScalarMul(sigma.x(), SkIntToScalar(3))),
                   SkScalarCeilToInt(SkScalarMul(sigma.y(), SkIntToScalar(3))));
     *dst = bounds;
@@ -270,8 +270,8 @@ bool SkBlurImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, const
         return false;
     }
     GrTexture* source = input.getTexture();
-    SkVector sigma, localSigma = SkVector::Make(fSigma.width(), fSigma.height());
-    ctx.ctm().mapVectors(&sigma, &localSigma, 1);
+    SkVector sigma = SkVector::Make(fSigma.width(), fSigma.height());
+    ctx.ctm().mapVectors(&sigma, 1);
     sigma.fX = SkMinScalar(sigma.fX, MAX_SIGMA);
     sigma.fY = SkMinScalar(sigma.fY, MAX_SIGMA);
     offset->fX = rect.fLeft;