SSE2 implementation of RGBA box blurs. This yields ~2X perf improvement on

src/opts/SkBlurImage_opts.h

Index: src/opts/SkBlurImage_opts.h
diff --git a/src/opts/SkBlurImage_opts.h b/src/opts/SkBlurImage_opts.h
new file mode 100644
index 0000000000000000000000000000000000000000..a8fb20935384f2b43cb8f446f3c37421ea8c5e5d
--- /dev/null
+++ b/src/opts/SkBlurImage_opts.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright 2013 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkBlurImage_opts_DEFINED
+#define SkBlurImage_opts_DEFINED
+
+#include "SkColorPriv.h"
+
+typedef void (*SkBoxBlurProc)(const SkPMColor* src, int srcStride, SkPMColor* dst, int kernelSize,
+                              int leftOffset, int rightOffset, int width, int height);
+
+bool SkBoxBlurGetPlatformProcs(SkBoxBlurProc* boxBlurX,
+                               SkBoxBlurProc* boxBlurY,
+                               SkBoxBlurProc* boxBlurXY);
+#endif