Really, I always assumed that Adobe successfully mitigated all the revenue risk by selling recurring Creative Studio/Cloud licenses, and that Flash was not a big chunk of revenue anymore. I remember Steve Jobs planning to kill Adobe or at least news blog reporting such intentions.[0]
Adobe stock has done pretty well over last half a decade even when compared with Google.[1]
[0] http://www.businessinsider.com/the-real-reason-steve-jobs-wa...
[1] https://www.google.com/finance?q=NASDAQ%3AADBE%2CGOOGL&ei=2j...