Check destination alignment for Q420 format when using SSE2.

BUG=96
TEST=none
Review URL: https://webrtc-codereview.appspot.com/861004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@387 16f28f9a-4ce2-e073-06de-1de4eb20be90

README.chromium

 Name: libyuv
 URL: http://code.google.com/p/libyuv/
-Version: 386
+Version: 387
 License: BSD
 License File: LICENSE
 

include/libyuv/version.h

@@ -11,6 +11,6 @@
 #ifndef INCLUDE_LIBYUV_VERSION_H_  // NOLINT
 #define INCLUDE_LIBYUV_VERSION_H_
 
-#define LIBYUV_VERSION 386
+#define LIBYUV_VERSION 387
 
 #endif  // INCLUDE_LIBYUV_VERSION_H_  NOLINT

source/convert.cc

@@ -544,7 +544,9 @@ int Q420ToI420(const uint8* src_y, int src_stride_y,
       YUY2ToYRow = YUY2ToYRow_Unaligned_SSE2;
       if (IS_ALIGNED(src_yuy2, 16) && IS_ALIGNED(src_stride_yuy2, 16)) {
         YUY2ToUV422Row = YUY2ToUV422Row_SSE2;
-        YUY2ToYRow = YUY2ToYRow_SSE2;
+        if (IS_ALIGNED(dst_y, 16) && IS_ALIGNED(dst_stride_y, 16)) {
+          YUY2ToYRow = YUY2ToYRow_SSE2;
+        }
       }
     }
   }