When I was doing the fix for 76303, I noticed this issue in a few places: http://trac.webkit.org/browser/trunk/Source/WebCore/platform/win/DragImageWin.cpp#L201 http://trac.webkit.org/browser/trunk/Source/WebKit/win/WebNodeHighlight.cpp#L157 There are a few things that could be done: 1. One could bake in SaveDC/RestoreDC into HWndDC and OwnPtr<HDC> -- likely OwnPtr<HDC> should become something else. Ideally paired with removing the code which restores state already. 2. One could put in checks into HWndDC and OwnPtr<HDC> to assert that the hdc is at its default state. (The state it was at when it was given to the class.) #1 seems the least error prone (and likely not very expensive these days). I'll leave this fix/decision up to people who work on this platform more often than I do.