libvpx: Pull from upstream

Current HEAD: 858fe955ae5a42a0006c974b0837df18b246986f

git log from upstream:
858fe955a vp9: fix definition for VP9E_SET_POSTENCODE_DROP
fa5083e8e Fix segmentation fault in hbd path
759d1de9d vp8 dec: Add flag to bring up threads.
38d98d870 vp8 idct dequant: resolve missing declarations
2e39962d7 vp8 blend: resolve missing declarations
0aeaf29b1 vp8 overlaps: resolve missing declaration
f485c67d0 vp9_get_blockiness: resolve missing declaration
5aeaf43c4 vp8 multi dimensional search: resolve missing declarations
8466728f8 vp8_copy32xn: resolve missing declaration
f479beeeb vpx_filter: resolve missing declarations
948e51696 vpx_clear_system_state: resolve missing declaration
9cf2e851d vp9 intra pred test: resolve -Wuninitialized warning
57d476bd8 arm neon: resolve missing declarations
46e17f0cb Fix OOB memory access on fuzzed data
6efdd9ad4 fix vp9 fdct_quant
ad57c72b9 VP9 firstpass: Bugfix when mi_col_start/end is odd
3271a7ed6 Increase memory size in non-greedy-mv
23f8b8317 Build pyramid motion field
c4c5c1d7e vp9: psnr diff thres for single vs multi threading.
95ac0cc9f Adaptively choose block sizes in temporal filtering
<...>

Test: none
BUG=b/122675483

Change-Id: I392f4fab4355476fcbe944986b9c7399c1888d07
diff --git a/README.android b/README.android
index 92739cd..7fc16a6 100644
--- a/README.android
+++ b/README.android
@@ -1,12 +1,12 @@
 Name: libvpx
 URL: http://www.webmproject.org
-Version: v1.7.0
+Version: v1.8.0
 License: BSD
 License File: libvpx/LICENSE
 
-Date: Wednesday January 24 2018
-Branch: origin/mandarinduck
-Commit: f80be22a1099b2a431c2796f529bb261064ec6b4
+Date: Wednesday January 16 2019
+Branch: origin/northernshoveler
+Commit: 858fe955ae5a42a0006c974b0837df18b246986f
 
 Description:
 Contains the sources used to compile libvpx.