Port SkBlurImage opts to SkOpts.

src/core/SkOpts.cpp

Index: src/core/SkOpts.cpp
diff --git a/src/core/SkOpts.cpp b/src/core/SkOpts.cpp
index 9ccc66de0840f291ea3182aa97e9ae7efadce4c7..d53749571883b1870f2248c7e4bdb208f4e162af 100644
--- a/src/core/SkOpts.cpp
+++ b/src/core/SkOpts.cpp
@@ -7,6 +7,7 @@
 
 #include "SkOnce.h"
 #include "SkOpts.h"
+#define SK_OPTS_NS portable

[djsollen, 2015/08/04 14:39:56]

given that you don't yet use this define I would remove it from this CL

[mtklein, 2015/08/04 14:46:44]

Let's leave it.  It's what it wants to be, modulo me figuring out why I can't
make it work in SkXfermode_opt.h.

 #include "SkXfermode_opts.h"
 
 #if defined(SK_CPU_X86)
@@ -47,6 +48,10 @@ namespace SkOpts {
     decltype(memset32)               memset32 = portable::memsetT<uint32_t>;
     decltype(create_xfermode) create_xfermode = SkCreate4pxXfermode;
 
+    decltype(box_blur_xx) box_blur_xx = nullptr;

[djsollen, 2015/08/04 14:39:56]

this is a break from previous versions where we default to the portable code. 
Why the switch?

[mtklein, 2015/08/04 14:46:44]

The portable blurs are in src/effects, and this keeps it that way.  We can
follow up by moving them to src/opts if you like.  I can see arguments for both
ways.

[djsollen, 2015/08/04 14:56:17]

I like the idea that SkOpts functions are always defined and you don't need to
do these null checks, but I'm ok to put that off to a follow up CL.

[mtklein_C, 2015/08/04 15:16:56]

I tried it and I'm convinced.  Done!

+    decltype(box_blur_xy) box_blur_xy = nullptr;
+    decltype(box_blur_yx) box_blur_yx = nullptr;
+
     // Each Init_foo() is defined in src/opts/SkOpts_foo.cpp.
     void Init_sse2();
     void Init_ssse3();