Element and selector can't be null in most places.
Created attachment 269271 [details]
Attachment 269271 [details] did not pass style-queue:
ERROR: Source/WebCore/css/SelectorChecker.cpp:623: An else if statement should be written as an if statement when the prior "if" concludes with a return, break, continue or goto statement. [readability/control_flow] 
Total errors found: 1 in 5 files
If any of these errors are false positives, please file a bug against check-webkit-style.