The Objective-C runtime doesn’t work so well with complex C++ types as arguments to methods. The methods end up building big complicated strings for use at runtime. While we never use these in WebKit, I believe the symbols themselves make the binary bigger and load slower (due to overhead making the strings unique). Accordingly, we should minimize the use of C++ types for arguments to Objective-C methods.
Created attachment 29577 [details] list of methods inside WebCore tree that might need to change
Bug 25210 is the part of this that in auto-generated DOM bindings.
Maybe we will do this one day, but I don’t think I need to keep this bug open just to remind me of the idea.