Avoid /arch:AVX[2] in Skia on Windows.

skia/BUILD.gn

Index: skia/BUILD.gn
diff --git a/skia/BUILD.gn b/skia/BUILD.gn
index c0e296e5fa2f5b3cec2d49e617db10f37f28bdce..133e00d4b0cd99e4ed39d6f0b7ed0174d0be0530 100644
--- a/skia/BUILD.gn
+++ b/skia/BUILD.gn
@@ -193,6 +193,8 @@ config("skia_library_config") {
                   # assembly code contains flow control(jmp or jcc) statements.
 
       "/wd4800",  # forcing value to bool 'true/false'(assigning int to bool).
+
+      "/wd4752",  # We use AVX but don't let the compiler do so itself.  See crbug.com/666707.

[brucedawson, 2016/11/18 18:21:30]

Wrap this line at 80 characters.

[mtklein_C, 2016/11/18 18:24:06]

Whoops, as you may have guessed, my editor is set at 100.

Done.

     ]
   }
 }
@@ -554,7 +556,7 @@ if (!skia_build_no_opts) {
         cflags = [ "-mavx" ]
       }
       if (is_win) {
-        cflags = [ "/arch:AVX" ]
+        defines = [ "SK_CPU_SSE_LEVEL=51" ]
       }
       visibility = [ ":skia_opts" ]
       configs -= [ "//build/config/compiler:chromium_code" ]
@@ -576,7 +578,7 @@ if (!skia_build_no_opts) {
         ]
       }
       if (is_win) {
-        cflags = [ "/arch:AVX2" ]
+        defines = [ "SK_CPU_SSE_LEVEL=52" ]
       }
       visibility = [ ":skia_opts" ]
       configs -= [ "//build/config/compiler:chromium_code" ]