Tweak getPropertyPriority to match recommendations
Adding Tests for Style Priority
Use else if
Adding Content Test for GetPropertyPriority
Revert "Adding Tests for Style Priority"
This reverts commit 8666a37f833b06c3e43f27acd8a9678e94425e55.
This just includes the .webidl file (with some of the functionality
commented out) and the stub implementations for the bindings.
This is another step towards #1721.