Drop compressed frames, not decoded ones in decode_with_drops

This should help with testing error resilience features.

Test is slightly modified to avoid build failures.

Change-Id: I471c033490b87768d596b784fa2107de94a5eb3b
diff --git a/examples/decode_with_drops.c b/examples/decode_with_drops.c
index c2f3c54..362f9ad 100644
--- a/examples/decode_with_drops.c
+++ b/examples/decode_with_drops.c
@@ -116,9 +116,6 @@
     int skip;
     const unsigned char *frame =
         aom_video_reader_get_frame(reader, &frame_size);
-    if (aom_codec_decode(&codec, frame, (unsigned int)frame_size, NULL))
-      die_codec(&codec, "Failed to decode frame.");
-
     ++frame_cnt;
 
     skip = (is_range && frame_cnt >= n && frame_cnt <= m) ||
@@ -126,6 +123,8 @@
 
     if (!skip) {
       putc('.', stdout);
+      if (aom_codec_decode(&codec, frame, (unsigned int)frame_size, NULL))
+        die_codec(&codec, "Failed to decode frame.");
 
       while ((img = aom_codec_get_frame(&codec, &iter)) != NULL)
         aom_img_write(img, outfile);
diff --git a/test/decode_with_drops.sh b/test/decode_with_drops.sh
index 5978312..0a603e3 100755
--- a/test/decode_with_drops.sh
+++ b/test/decode_with_drops.sh
@@ -54,8 +54,8 @@
       file="${AOM_TEST_OUTPUT_DIR}/test_encode.ivf"
       encode_yuv_raw_input_av1 "${file}" --ivf
     fi
-    # Drop frames 2 and 3.
-    decode_with_drops "${file}" "av1" "2-3"
+    # Drop frames 3 and 4.
+    decode_with_drops "${file}" "av1" "3-4"
 
     # Test pattern mode: Drop 3 of every 4 frames.
     decode_with_drops "${file}" "av1" "3/4"