inherit parent iframe's nwuseragent attribute
inherit parent iframe's nwuseragent attribute

Conflicts:
	Source/core/loader/FrameLoader.cpp

ondra-novak/blink,ondra-novak/blink,ondra-novak/blink,ondra-novak/blink,ondra-novak/blink,ondra-novak/blink,ondra-novak/blink,ondra-novak/blink,ondra-novak/blink