Update gyp to support SSSE3/SSE4 compile checks.

skia/skia_library_opts.gyp

Index: skia/skia_library_opts.gyp
diff --git a/skia/skia_library_opts.gyp b/skia/skia_library_opts.gyp
index 32c39793a77ab7d0070f84c045b93f4a65462b72..37f5eb44addf19bb387eb61118642ac4367e92a5 100644
--- a/skia/skia_library_opts.gyp
+++ b/skia/skia_library_opts.gyp
@@ -203,6 +203,9 @@
               'config/win',
             ],
           },
+          'defines' : [
+            'SK_CPU_SSE_LEVEL=31'
+          ],
         }],
         [ 'target_arch != "arm" and target_arch != "arm64" and \
            target_arch != "mipsel"', {
@@ -240,6 +243,11 @@
             'GCC_ENABLE_SSE41_EXTENSIONS': 'YES',
           },
         }],
+        [ 'OS == "win"', {
+          'defines' : [
+            'SK_CPU_SSE_LEVEL=41'
+          ],
+        }],
         [ 'target_arch == "x64"', {
           'sources': [
             '../third_party/skia/src/opts/SkBlitRow_opts_SSE4_x64_asm.S',