r84990 added functions to IWebViewPrivate.idl, but didn't add them to the bottom of the file, causing nighties to break. To fix this, these functions need to be moved to the bottom of the file. <rdar://problem/9358635>
Created attachment 92160 [details] [PATCH] Fix
*** Bug 60043 has been marked as a duplicate of this bug. ***
Landed in r85691.