[webkit-dev] Experimental features enabled by default

[Michael Catanzaro]

Hi,

We're a lot closer after r233227!

There is still IsSecureContextAttributeEnabled. Shall we switch the 
default value of that one to use DEFAULT_EXPERIMENTAL_FEATURES_ENABLED 
instead of true?

We should also move CSSAnimationTriggersEnabled to the experimental 
features section of the file, and add the category tag. 
FullScreenEnabled and EncryptedMediaAPIEnabled should also be moved 
down in the file.

Then we can just update the comment to indicate that custom values like 
DEFAULT_SERVICE_WORKERS_ENABLED are fine as long as they're thoughtful 
and consider ENABLE(EXPERIMENTAL_FEATURES), and that will take care of 
the other cases.

Michael