Fix issues on EBML lacing block parsing
Fix issues on EBML lacing block parsing

Fix EBML lacing block parsing when attempting to parse the last frame
on single-frame videos and assertion when frame_count is lower
than actual data in the file.

Change-Id: I223e30be54970ef75126c6c4ee3401cbeb92e02f

webmproject/libwebm,zofuthan/libwebm,felipebetancur/libwebm,felipebetancur/libwebm,zofuthan/libwebm,webmproject/libwebm,webmproject/libwebm