The code mixes IntPoint, IntSize and int, which makes it hard to read, let alone change. The rest of WebCore assumes that an offset is an IntSize but ScrollableArea uses IntPoint / FloatPoint to represent offsets. I don't know if there is a consensus on offsets being points vs sizes but the usage seems to point at size. This change aims at simplifying the logic by switching as much of RenderLayer to using IntSize for manipulating scroll offsets. This has the added benefit of simplifying some of the computations by doing both coordinates with one line of code.
Created attachment 147706 [details] Proposed change. Use IntSize when applicable.
Comment on attachment 147706 [details] Proposed change. Use IntSize when applicable. Attachment 147706 [details] did not pass win-ews (win): Output: http://queues.webkit.org/results/12956539
Created attachment 147846 [details] Version 2. Forgot to update WebKit callers.
Comment on attachment 147846 [details] Version 2. Forgot to update WebKit callers. LGTM.
Comment on attachment 147846 [details] Version 2. Forgot to update WebKit callers. Clearing flags on attachment: 147846 Committed r120832: <http://trac.webkit.org/changeset/120832>
All reviewed patches have been landed. Closing bug.