[webkit-dev] Pixel testing and WebKit2

[Simon Fraser]

After various fixes, pixel tests now work reasonably well in WebKitTestRunning (i.e. when running with WebKit2).

One final step is enabling mock scrollbars in DRT/WTR <https://bugs.webkit.org/show_bug.cgi?id=68134>. The goal of using mock scrollbars is to reduce the pixel differences between platforms, so that we can share more common pixel results. However, on Mac, mock scrollbars will only work in WebKit2 (since AppKit draws the WK1 scrollbars).

For this reason, I'd like to propose that on Mac, all pixel testing is done using WebKit2, which you can get by passing "-2" to run-webkit-tests or new-run-webkit-tests. I can fix the scripts to print a warning if you pass --pixel without -2 (or make --pixel use -2 by default).

Any objections?

Simon