SSSE3 scaling test detect SSSE3 before running

Bug: libyuv:755
Test: ~/intelsde/sde -p4p -- out/Release/libyuv_unittest --gtest_filter=LibYUVScaleTest*
Change-Id: Ibb0c908c38efc49dc56e86fa54ae7bd48ced02b5
Reviewed-on: https://chromium-review.googlesource.com/756363Reviewed-by: Cheng Wang <wangcheng@google.com>

unit_test/scale_test.cc

@@ -366,7 +366,7 @@ TEST_SCALETO(Scale, 1280, 720)
 #undef TEST_SCALETO
 
 #ifdef HAS_SCALEROWDOWN2_SSSE3
-TEST_F(LibYUVScaleTest, TestScaleOdd) {
+TEST_F(LibYUVScaleTest, TestScaleRowDown2Box_Odd_SSSE3) {
   SIMD_ALIGNED(uint8 orig_pixels[128 * 2]);
   SIMD_ALIGNED(uint8 dst_pixels_opt[64]);
   SIMD_ALIGNED(uint8 dst_pixels_c[64]);
@@ -374,6 +374,10 @@ TEST_F(LibYUVScaleTest, TestScaleOdd) {
   memset(dst_pixels_opt, 0, sizeof(dst_pixels_opt));
   memset(dst_pixels_c, 0, sizeof(dst_pixels_c));
 
+  int has_ssse3 = TestCpuFlag(kCpuHasSSSE3);
+  if (!has_ssse3) {
+    printf("Warning SSSE3 not detected; Skipping test.\n");
+  } else {
     // TL
     orig_pixels[0] = 255u;
     orig_pixels[1] = 0u;
@@ -447,6 +451,7 @@ TEST_F(LibYUVScaleTest, TestScaleOdd) {
     for (int i = 0; i < 64; ++i) {
       EXPECT_EQ(dst_pixels_c[i], dst_pixels_opt[i]);
     }
+  }
 }
 #endif  // HAS_SCALEROWDOWN2_SSSE3