third_party/libwebm: pull from upstream.
Upstream hash: a58c32339e06e5d672a58cdd5844cea0a661e735
Changes from upstream since last update:
a58c323 mkvmuxer: Add codec id constant for VP10.
714f3c4 mkvparser: validate results in EBMLHeader::Parse.
cec98d4 mkvparser: Correct the ReadID implementation.
eb36ae4 Merge changes I029a268e,Ia272b150,I5c4d1bbc,Ia47a2478,I3a2e2226
229f493 Merge "mkvparser: Segment::AppendCluster asserts to error checks."
287faf9 Merge "mkvparser: Segment::DoLoadClusterUnknownSize asserts to error checks."
1a87b59 Merge "mkvparser: Segment assert clean up."
d26ec69 mkvparser: Cluster::Parse clean up.
f2029be mkvparser: Disallow EBML IDs equal to 0.
19f5694 mkvparser: Cluster::Load clean up.
27a07c1 mkvparser: Segment::Load asserts to error checks.
d0313dd mkvparser: Segment::PreloadCluster asserts to error checks.
b108695 mkvparser: Segment::AppendCluster asserts to error checks.
4630f80 mkvparser: Segment::DoLoadClusterUnknownSize asserts to error checks.
841a9b5 mkvparser: Segment assert clean up.
8c4ca2e Merge "mkvparser: Make mkvparser namespace usage uniform."
49ae6f0 Merge "mkvparser: Fix include order."
0735bb5 mkvparser: Make mkvparser namespace usage uniform.
93b24c4 mkvparser: Fix include order.
a57d660 sample_muxer: fix Segment memory leak on error
1c5bd94 mkvparser: Cues, change asserts to error checks.
7f77201 Merge "mkvparser: Add ReadID."
795fd56 mkvparser: set kMaxAllocSize explicitly
23bb18b mkvparser: Add ReadID.
7b57e37 mkvparser: add SafeArrayAlloc.
83a1f68 mkvparser: Remove buf_t typedef.
5074714 Merge changes Ia1265a63,I799d54df,Icfc582e4,I3425f608
b181105 Merge changes Ie4318152,I1e65f30f
06b4337 Block::Parse: replace pos asserts w/checks
b366a98 Cluster::ParseBlockGroup: replace pos asserts w/checks
2857b23 Tags::*::Parse: replace pos asserts w/checks
f1b2cfa Chapters::*::Parse: replace pos asserts w/checks
ca80629 Merge "mkvparser: Cues::PreloadCuePoint now returns bool."
6b4b297 Block::Parse: use int64 to aggregate laced frame sizes
c0d2c98 UnserializeFloat: check result for Inf/NaN
1a6dc4f mkvparser: Cues::PreloadCuePoint now returns bool.
275ac22 mkvparser: Cluster::Create clean up.
064f2ee Segment::PreloadCluster(): return a bool status
3778408 Segment::AppendCluster(): return a bool status
e86d046 mkvparser: check Cluster::Create() return
f9885b5 mkvparser: check allocations
21ee398 mkvparser: Segment::Load fail w/missing info/tracks
08fb654 Merge changes I264e68b2,Ife6190a4,Ibf37245f,I06efadb5,I88b5dfec, ...
c896095 mkvparser/Cluster: convert asserts to failure returns
680b4bf mkvparser/Tracks: convert asserts to failure returns
5889e6c mkvparser/Track: convert asserts to failure returns
5135c4c mkvparser/ContentEncoding: convert asserts to failure returns
b0e4f32 mkvparser/Cues: convert asserts to failure returns
13ccc7f mkvparser/UnserializeInt: fix sign flip
db3f9bb mkvparser/SeekHead: convert asserts to failure returns
8de3654 mkvparser/Segment: convert asserts to failure returns
fa2aa7d SeekHead::Parse(): fix assertion failure
d9bdade sample{,_muxer}: check SegmentInfo::GetInfo() return
07a9cf7 Merge "mkvparser: Remove some asserts."
c56ee29 mkvparser: Remove some asserts.
d901324 Merge "mkvparser: Remove some asserts from SegmentInfo::Parse."
7f7d898 Fix case sensitivity issue in iosbuild.sh.
42fe2cd mkvparser: Remove some asserts from SegmentInfo::Parse.
8bccd9c Merge "mkvparser: avoid rollover in UnserializeInt()."
7a2fa0d mkvparser: avoid rollover in UnserializeInt().
44f5ce6 mkvparser: Disallow durations in seconds greater than LONG_LONG_MAX.
b521e30 Merge "mkvparser: Segment::ParseHeaders() avoid rollover and bad int sizes."
7680e2a mkvparser: Check for errors in Match().
39a315f mkvparser: Segment::ParseHeaders() avoid rollover and bad int sizes.
f250ace mkvparser: Handle invalid lengths and rollover in ParseElementHeader().
cd96a76 mkvparser: Avoid rollover/truncation in UnserializeString().
8e8b3db Merge "mkvparser: Add error checking in Block::Parse."
82b7e5f sample: correct mbstowcs() error check
04d7809 sample: check allocation return
986b64b mkvparser: Add error checking in Block::Parse.
Change-Id: I39beef84962d6341f8ce53be06807b3e2068f777
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