This one was a little more tricky.
Created attachment 8567 [details] patch Like the other split patches, this requires the lander to do some work to split the files on their end (ussually just running a script). It is a little more complicated than some of the others as StyleSelector.h, CSSRuleData.h and CSSRuleDataList.h all do not have implementation (.cpp) files and thus only require cssstyleselector.h to be copied. In addition, CSSRuleSet.h and CSSRuleSet.cpp come from within cssstyleselector.cpp and require to copies of it. Lastly, I could not find a way to convert cssstyleselector.h and cssstyleselector.cpp into CSSStyleSelector.h and CSSStyleSelector.cpp due to svn not understanding the case change.
Comment on attachment 8567 [details] patch Looks great. But there's no patch here for the project files, nor for ChangeLog. Need to include those.
Please feel free to reopen if you'd like to revisit this work.