Reimplement NV21ToARGB to allow different color matrix.

include/libyuv/planar_functions.h

 /*
  *  Copyright 2011 The LibYuv Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS. All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 127 matching lines @@
                uint8* dst_argb, int dst_stride_argb,
                int width, int height);
 
 // Convert NV12 to RGB565.
 LIBYUV_API
 int NV12ToRGB565(const uint8* src_y, int src_stride_y,
                  const uint8* src_uv, int src_stride_uv,
                  uint8* dst_rgb565, int dst_stride_rgb565,
                  int width, int height);
 
-// Convert NV21 to RGB565.
-LIBYUV_API
-int NV21ToRGB565(const uint8* src_y, int src_stride_y,
-                 const uint8* src_uv, int src_stride_uv,
-                 uint8* dst_rgb565, int dst_stride_rgb565,
-                 int width, int height);
-
 // I422ToARGB is in convert_argb.h
 // Convert I422 to BGRA.
 LIBYUV_API
 int I422ToBGRA(const uint8* src_y, int src_stride_y,
                const uint8* src_u, int src_stride_u,
                const uint8* src_v, int src_stride_v,
                uint8* dst_bgra, int dst_stride_bgra,
                int width, int height);
 
 // Convert I422 to ABGR.
@@ skipping 279 matching lines @@
 int ARGBSobelXY(const uint8* src_argb, int src_stride_argb,
                 uint8* dst_argb, int dst_stride_argb,
                 int width, int height);
 
 #ifdef __cplusplus
 }  // extern "C"
 }  // namespace libyuv
 #endif
 
 #endif  // INCLUDE_LIBYUV_PLANAR_FUNCTIONS_H_  NOLINT