Mexigonus minutus (F. O. Pickard-Cambridge, 1901) - Jumping Spider
This species is apparently a relatively recent introduction to California. There is a May 2013 record on BugGuide submitted by L. Elliott (photographed and identified by L. Leonard). The spiders shown in the video were identified by GB Edwards and are in the FSCA. In his review of the Euophryinae north of Mexico Edwards says this genus is likely an endemic Nearctic genus, with possible Neotropical relatives.
G. B. Edwards (pers. comm.); Edwards, 2002