Fork VP9 and VP10 codebase

This commit folks the VP9 and VP10 codebase and makes libvpx
support VP8, VP9, and VP10.

Change-Id: I81782e0b809acb3c9844bee8c8ec8f4d5e8fa356

test/decode_api_test.cc

@@ -26,6 +26,9 @@ TEST(DecodeAPI, InvalidParams) {
 #endif
 #if CONFIG_VP9_DECODER
     &vpx_codec_vp9_dx_algo,
+#endif
+#if CONFIG_VP10_DECODER
+    &vpx_codec_vp10_dx_algo,
 #endif
   };
   uint8_t buf[1] = {0};