FrameLoaderClientImpl::createFrame does not need marginWidth, marginHeight or allowsScrolling arguments

createFrame ignores all these arguments so we can remove them which means we can
remove HTMLFrameOwnerElement::marginWidth(), marginHeight() and allowScrollingInContentFrame()
in addition to making HTMLFrameElementBase::marginHeight() and marginWidth() non-virtual.

Review URL: https://chromiumcodereview.appspot.com/23498003

git-svn-id: svn://svn.chromium.org/blink/trunk@156758 bbb929c8-8fbe-4397-9dbb-9b2b20218538