Disable SSE4 S32A_Opaque blit.

src/opts/SkBlitRow_opts_SSE4.h

Index: src/opts/SkBlitRow_opts_SSE4.h
diff --git a/src/opts/SkBlitRow_opts_SSE4.h b/src/opts/SkBlitRow_opts_SSE4.h
index f202aa5139129a72e6bc5d65c60d10874d4ce9eb..600e669893dd32bb156d3b5cfd2686e50eeb715b 100644
--- a/src/opts/SkBlitRow_opts_SSE4.h
+++ b/src/opts/SkBlitRow_opts_SSE4.h
@@ -10,6 +10,8 @@
 
 #include "SkBlitRow.h"
 
+#ifdef CRBUG_399842_FIXED
+
 /* Check if we are able to build assembly code, GCC/AT&T syntax:
  *  1) Clang and GCC are generally OK.  OS X's old LLVM-GCC 4.2 can't handle it;
  *  2) We're intentionally not linking this in even when supported (Clang) on Windows;
@@ -25,5 +27,7 @@ extern "C" void S32A_Opaque_BlitRow32_SSE4_asm(SkPMColor* SK_RESTRICT dst,
 #define SK_ATT_ASM_SUPPORTED
 #endif
 
+#endif // CRBUG_399842_FIXED
+
 #endif