As discussed in https://bugs.webkit.org/show_bug.cgi?id=87127 and later on IRC, there are occasions where the feature might be supported (more or less) completely by the Gtk port but is not ready for shipping in release versions due to incompleteness or instability (spec-wise). Two features that might fall under this categorization in the feature are perhaps those guarded by the ENABLE_GAMEPAD and ENABLE_MEDIA_STREAM defines. To achieve this a configuration option should be added - when enabled (through build-webkit or manually) the features are enabled and compiled, when disabled (the default value, when compiling a release) the features are not included in the build.
This blocking bug #87127 makes more sense.
Created attachment 151104 [details] Patch
Comment on attachment 151104 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=151104&action=review > configure.ac:1510 > + Unstable features : $enable_unstable_features Perhaps it would be better to hide this option. I don't think we want downstream turning it on.
(In reply to comment #3) > (From update of attachment 151104 [details]) > View in context: https://bugs.webkit.org/attachment.cgi?id=151104&action=review > > > configure.ac:1510 > > + Unstable features : $enable_unstable_features > > Perhaps it would be better to hide this option. I don't think we want downstream turning it on. Very well, I'll remove it when landing.
Landed in http://trac.webkit.org/changeset/121988.