Following up on a suggestion by Darin Adler in bug 157252, comment 2, we should extract the policy logic for when to apply a quirk or workaround from file Source/WebKit/mac/WebView/WebView.mm into a separate header file and implementation file. For convenience, the following is what Darin wrote: [[ We should ... [group] ... functions that make decisions about ... quirks and workarounds in a header analogous to the RuntimeApplicationChecks one. This header would never mention specific application but would just list all the different quirks. The implementation file would contain all the expressions used to decide when each quirk applies, and comments about why each implements the right policy. The implementations of the quirks would continue to be distributed throughout the code, but the policy of which quirks apply when would be grouped together. ]]