Have SVGTextContentElement inherit SVGGraphicsElement

Have SVGTextContentElement inherit SVGGraphicsElement instead of
SVGStyledElement in order to match the latest SVG2 specification:
https://svgwg.org/svg2-draft/text.html#InterfaceSVGTextContentElement

This patch also removes the SVGTransformable and SVGLocatable IDL
interfaces as they are no longer needed (were merged into
SVGGraphicsElement in the latest specification).

Conversion to absolute (user agent) coordinates in the svg/text
tests is fixed to use SVGGraphicsElement::getScreenCTM() instead
of SVGGraphicsElement::getTransformToElement(). The previous code
was working until now due to a bug in getTransformToElement(),
which was not taking into consideration the CTM of the
SVGTextElement (as it was not recognized as a "locatable" element).
Now that SVGTextElement inherits from SVGGraphicsElement, it is
properly recognized as a "locatable" element by
getTransformToElement().

This is one step towards getting rid of multiple inheritance in
SVG.

BUG=256600

Review URL: https://chromiumcodereview.appspot.com/18503004

git-svn-id: svn://svn.chromium.org/blink/trunk@153432 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Suppress fast/js/JSON-stringify.html on mac release

This happened around chromium r209703 (clang roll to 184830).

TBR=thakis,senorblanco
BUG=

Review URL: https://codereview.chromium.org/18543005

git-svn-id: svn://svn.chromium.org/blink/trunk@153433 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Rebaseline after "Remove calls to updateMarqueePosition from RenderLayer"

Just some timing difference with <marquee>

TBR=leviw@chromium.org

Review URL: https://codereview.chromium.org/18564002

git-svn-id: svn://svn.chromium.org/blink/trunk@153434 bbb929c8-8fbe-4397-9dbb-9b2b20218538