I noticed this also... I have about 1.0% on GA showing Chrome 1.5 and 100% (according to GA) is "Mobile" and 97% is "Samsung" brand. Taking a look at this page - http://www.webapps-online.com/online-tools/user-agent-strings/dv/brand125499/samsung-galaxy-note-iii - makes me wonder if GA is counting strings like Version/1.5 Chrome/28.0.1500.94
as Chrome 1.5.
My best guess would be Google Analytics just screwed up the parsing of the newer Samsung user agent strings, which (again, according to that webpage) looks to be Chrome 28. At least that's what I'm going to mark it down as.
(Sorry for the 4 month late response. Figured other people might be Googling this also.)
UPDATE: These are the entries for "Mobile Device Info" on my GA results for Chrome 1.5...
Samsung SCH-I545 Galaxy S IV
Samsung SCH-I337 Galaxy S IV
Samsung GT-I9500 Galaxy S IV
Samsung SGH-M919 Galaxy S IV
Samsung SM-N900V Galaxy Note 3
Samsung SM-N900A Galaxy Note 3
Samsung SM-N900P Galaxy Note 3
Samsung SM-N900T Galaxy Note 3
Samsung SGH-I537 Galaxy S4 Active
Samsung SM-P600 Galaxy Note 10.1 2014
Samsung SM-T520 Galaxy Tab Pro 10.1
Samsung SGH-I337M Galaxy S IV
Samsung SM-P900 Galaxy Note Pro
Samsung GT-I9505 Galaxy S IV
Samsung SCH-M919 Galaxy S IV
Samsung SM-T900 Galaxy Tab Pro 12.2
Samsung SCH-R970 Galaxy S IV
Samsung SCH-R970X Galaxy S IV
Samsung SM-N9005 Galaxy Note 3
Samsung SM-N900W8 Galaxy Note 3
Samsung SM-T320 Galaxy Tab Pro 8.4
Samsung SPH-L720T Galaxy S4
Samsung SM-P905V Galaxy Note Pro
All of these show potential user agents with Version/1.5 Chrome/28.0.1500.94
, which should be interpretted as Chrome 28, not 1.5.