Make SSE2/Neon convolution functions not to read extra bytes

src/core/SkConvolver.h

Index: src/core/SkConvolver.h
diff --git a/src/core/SkConvolver.h b/src/core/SkConvolver.h
index 4e23f6cc17a39abde07c24a6d7ab41afe7eed89b..28a08dfa6800411bf2a9dd0b5692f53cb0209ce8 100644
--- a/src/core/SkConvolver.h
+++ b/src/core/SkConvolver.h
@@ -157,17 +157,11 @@ typedef void (*SkConvolveHorizontally_pointer)(
     const SkConvolutionFilter1D& filter,
     unsigned char* outRow,
     bool hasAlpha);
-typedef void (*SkConvolveFilterPadding_pointer)(
-    SkConvolutionFilter1D* filter);
 
 struct SkConvolutionProcs {
-  // This is how many extra pixels may be read by the
-  // conolve*horizontally functions.
-    int fExtraHorizontalReads;
     SkConvolveVertically_pointer fConvolveVertically;
     SkConvolve4RowsHorizontally_pointer fConvolve4RowsHorizontally;
     SkConvolveHorizontally_pointer fConvolveHorizontally;
-    SkConvolveFilterPadding_pointer fApplySIMDPadding;
 };