Cleanup: Remove unneeded SSE2 checks and unused code.

media/base/simd/convert_yuv_to_rgb_x86.cc

Index: media/base/simd/convert_yuv_to_rgb_x86.cc
diff --git a/media/base/simd/convert_yuv_to_rgb_x86.cc b/media/base/simd/convert_yuv_to_rgb_x86.cc
index 969890dbbefd386e0754d19c24e00000b52d44f0..2e6f5e30ab0f57518dcbaba852e9b56c3715eab0 100644
--- a/media/base/simd/convert_yuv_to_rgb_x86.cc
+++ b/media/base/simd/convert_yuv_to_rgb_x86.cc
@@ -14,34 +14,6 @@
 
 namespace media {
 
-void ConvertYUVToRGB32_MMX(const uint8* yplane,
-                           const uint8* uplane,
-                           const uint8* vplane,
-                           uint8* rgbframe,
-                           int width,
-                           int height,
-                           int ystride,
-                           int uvstride,
-                           int rgbstride,
-                           YUVType yuv_type) {
-  unsigned int y_shift = GetVerticalShift(yuv_type);
-  for (int y = 0; y < height; ++y) {
-    uint8* rgb_row = rgbframe + y * rgbstride;
-    const uint8* y_ptr = yplane + y * ystride;
-    const uint8* u_ptr = uplane + (y >> y_shift) * uvstride;
-    const uint8* v_ptr = vplane + (y >> y_shift) * uvstride;
-
-    ConvertYUVToRGB32Row_MMX(y_ptr,
-                             u_ptr,
-                             v_ptr,
-                             rgb_row,
-                             width,
-                             GetLookupTable(yuv_type));
-  }
-
-  EmptyRegisterState();
-}
-
 void ConvertYUVAToARGB_MMX(const uint8* yplane,
                            const uint8* uplane,
                            const uint8* vplane,