Correctly report "Unsupported bitstream profile"

For vp9 decoder build without profile 2 and profile 3 support, this
commit changes to report error "Unsupported bitstream profile" for
input streams in profile 2 or 3, rather than other misleading error
information.

In addition, one of the invalid files in unit tests is actually coded
profile 2, this commit makes it tested only when the decoder is built
with vp9-highbitdepth.

This fixes issue #1028.

Change-Id: I8b6c1210787c8f89c703a546687dcf973ac20fc0

test/decode_api_test.cc

@@ -129,8 +129,13 @@ TEST(DecodeAPI, Vp9InvalidDecode) {
   vpx_codec_ctx_t dec;
   EXPECT_EQ(VPX_CODEC_OK, vpx_codec_dec_init(&dec, codec, NULL, 0));
   const uint32_t frame_size = static_cast<uint32_t>(video.frame_size());
+#if CONFIG_VP9_HIGHBITDEPTH
   EXPECT_EQ(VPX_CODEC_MEM_ERROR,
             vpx_codec_decode(&dec, video.cxdata(), frame_size, NULL, 0));
+#else
+  EXPECT_EQ(VPX_CODEC_UNSUP_BITSTREAM,
+            vpx_codec_decode(&dec, video.cxdata(), frame_size, NULL, 0));
+#endif
   vpx_codec_iter_t iter = NULL;
   EXPECT_EQ(NULL, vpx_codec_get_frame(&dec, &iter));