Rewriting MatrixConvolution image filter with SSE and AVX2

src/opts/SkMatrixConvolutionImageFilter_opts_SSE.h

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkMatrixConvolutionImageFilter_opts_SSE_DEFINED
+#define SkMatrixConvolutionImageFilter_opts_SSE_DEFINED
+
+#include "SkScalar.h"
+#include "SkSize.h"
+#include "SkPoint.h"
+
+
+namespace sk_sse {
+
+void SkMatrixConvolutionImageFilter_filterPixels_SSE(
+                                                     const SkBitmap& src,
+                                                     SkBitmap* result,
+                                                     const SkIRect& r,
+                                                     const SkIRect& bounds,
+                                                     bool convolveAlpha,
+                                                     SkScalar* kernel,
+                                                     const SkISize& kernel_size,
+                                                     const SkIPoint&  kernel_offset, SkScalar gain,
+                                                     SkScalar bias);
+
+}
+
+#endif