checks for valid UTF-8 and fallback to the doc charset, bug 161479, r=shanjian, sr=jst, a=dbaron. git-svn-id: svn://10.0.0.236/trunk@129064 18797224-902f-48f8-a5cc-f745e15eee43
checks for valid UTF-8 and fallback to the doc charset, bug 161479, r=shanjian, sr=jst, a=dbaron. git-svn-id: svn://10.0.0.236/trunk@129064 18797224-902f-48f8-a5cc-f745e15eee43