We hardcode Cmd+B and Cmd+I in WebKit1 for historic reasons, but it doesn't look like there is any need to do this in WebKit2.
I tested GMail and iCloud e-mail, and these shortcuts work there even without this code (presumably because both implemented them in JS for Firefox on Mac). Mail.app has these shortcuts in menu, so again, hardcoding is unnecessary.
The reason I want to remove this is that _handleStyleKeyEquivalent looks at EditorState, which is not going to be supported in the future.
Created attachment 225387 [details]
Comment on attachment 225387 [details]
Clearing flags on attachment: 225387
Committed r164818: <http://trac.webkit.org/changeset/164818>
All reviewed patches have been landed. Closing bug.