Do not copy m_originatingLine in FloatingObject::unsafeClone

Copying m_originatingLine breaks the invariant that m_originatingLine
must be owned by m_renderer for the FloatingObject instance.

BUG=341791

Review URL: https://codereview.chromium.org/159023002

git-svn-id: svn://svn.chromium.org/blink/trunk@167067 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove 2 unnecessary null checks from SVGSVGElement.cpp

Now that undefined/null checking is done in bindings
(for [StrictTypeChecking]), per this CL:
Add [StrictTypeChecking] to the SVGGeometryElement interface
https://codereview.chromium.org/144463014/
...we can remove unnecessary checks.
Here are 2 in SVGSVGElement.cpp, which was inconsistent
(didn't have checks for others).

Noticed this in the test case svg/dom/undefined-null.html added in:
Add tests for |undefined| and |null| in SVG interfaces
https://codereview.chromium.org/159973005/
...as some tests that would be expected to throw just failed.

TBR=haraken
TBR=kouhei

Review URL: https://codereview.chromium.org/162553002

git-svn-id: svn://svn.chromium.org/blink/trunk@167068 bbb929c8-8fbe-4397-9dbb-9b2b20218538