Clean the SVGSVGElement interface IDL

Remove some weird looking uses of [Default=Undefined] on suspendRedraw,
unsuspendRedraw and getElementById.
This means that TypeErrors will be thrown for the 0 arguments case. This
is consistent with Gecko.

Since the *Redraw* methods are deprecated (except forceRedraw), remove
the comment about (WebKit) bug# (11275, dupe of 10408) and move the
implementation stubs to the header file.

Review URL: https://codereview.chromium.org/131473011

git-svn-id: svn://svn.chromium.org/blink/trunk@167078 bbb929c8-8fbe-4397-9dbb-9b2b20218538