libvpx: Pull from upstream

source/libvpx/vpx/vp8dx.h

Index: source/libvpx/vpx/vp8dx.h
diff --git a/source/libvpx/vpx/vp8dx.h b/source/libvpx/vpx/vp8dx.h
index 83898bf8496c608fe29b360c691660ef3c9f379f..bc9cb1a62fc3adcfd7fd79f8dbc94f5611682a05 100644
--- a/source/libvpx/vpx/vp8dx.h
+++ b/source/libvpx/vpx/vp8dx.h
@@ -106,6 +106,13 @@ enum vp8_dec_control_id {
    */
   VP9_INVERT_TILE_DECODE_ORDER,
 
+  /** control function to set the skip loop filter flag. Valid values are
+   * integers. The decoder will skip the loop filter when its value is set to
+   * nonzero. If the loop filter is skipped the decoder may accumulate decode
+   * artifacts. The default value is 0.
+   */
+  VP9_SET_SKIP_LOOP_FILTER,
+
   VP8_DECODER_CTRL_ID_MAX
 };