Make deadline mode not depend on frame duration.
Make deadline mode not depend on frame duration.

Backwards compatible with old API.

cherry-picked #02ae3dd3 from aom/master.

Change-Id: I65aa43f84bb9491e8cca73fe444094c2622b0187

mbebenita/aom,luctrudeau/aom,smarter/aom,GrokImageCompression/aom,GrokImageCompression/aom,smarter/aom,luctrudeau/aom,mbebenita/aom,mbebenita/aom,luctrudeau/aom,mbebenita/aom,mbebenita/aom,mbebenita/aom,mbebenita/aom,smarter/aom,smarter/aom,mbebenita/aom,GrokImageCompression/aom,GrokImageCompression/aom,luctrudeau/aom,mbebenita/aom,smarter/aom,luctrudeau/aom,luctrudeau/aom,GrokImageCompression/aom,smarter/aom,GrokImageCompression/aom