webm_parser: Add new enum values

For the new stereo mode, see https://github.com/google/spatial-media/blob/master/docs/spherical-video-v2-rfc.md#webm-matroska
For the new color primaries, see ISO/IEC 23001-8:2016

Change-Id: I92c2bb0fedc2b1895d893ad55095d29c811c0dcf
diff --git a/webm_parser/include/webm/dom_types.h b/webm_parser/include/webm/dom_types.h
index c37b0fc..7ae4a0c 100644
--- a/webm_parser/include/webm/dom_types.h
+++ b/webm_parser/include/webm/dom_types.h
@@ -783,6 +783,17 @@
   kSmpteSt4281 = 10,
 
   /**
+   Society of Motion Picture and Television Engineers RP 431-2 (a.k.a. DCI-P3).
+   */
+  kSmpteRp431 = 11,
+
+  /**
+   Society of Motion Picture and Television Engineers EG 432-1
+   (a.k.a. DCI-P3 D65).
+   */
+  kSmpteEg432 = 12,
+
+  /**
    JEDEC P22 phosphors/EBU Tech. 3213-E (1975).
    */
   kJedecP22Phosphors = 22,
@@ -1046,6 +1057,12 @@
    Both eyes are laced in one block, right eye is first.
    */
   kBlockLacedRightFirst = 14,
+
+  /**
+   Stereo, but the layout for the left and right eyes is application dependent
+   and must be determined from other data (like the ProjectionPrivate element).
+   */
+  kStereoCustom = 15,
 };
 
 /**