Disable SSE4 code.

Chrome canary failing to link chrome:
http://108.170.220.120:10115/builders/Canary-Chrome-Ubuntu13.10-Ninja-x86_64-ToT/builds/1009/steps/BuildChrome/logs/stdio

BUG=skia:
NOTRY=true
R=mtklein@google.com, rmistry@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/361493002
diff --git a/src/opts/SkBlitRow_opts_SSE4.h b/src/opts/SkBlitRow_opts_SSE4.h
index 6c6276e..b6ab140 100644
--- a/src/opts/SkBlitRow_opts_SSE4.h
+++ b/src/opts/SkBlitRow_opts_SSE4.h
@@ -18,7 +18,9 @@
                                                const SkPMColor* SK_RESTRICT src,
                                                int count, U8CPU alpha);
 
-#define SK_ATT_ASM_SUPPORTED
+// Temporarily disabled.  Chrome canary bot fails to link chrome with error:
+//   lib/libskia.so: error: undefined reference to 'S32A_Opaque_BlitRow32_SSE4_asm'
+//#define SK_ATT_ASM_SUPPORTED
 #endif
 
 #endif