Revert of Web Animations API: Support non-animatable properties being animated via element.animate() (https://codereview.chromium.org/225653003/)

Reason for revert:
ASSERTION FAILED: (position != AbsolutePosition && position != FixedPosition) || isBox()
../../third_party/WebKit/Source/core/rendering/RenderObject.h(652) : void WebCore::RenderObject::setPositionState(WebCore::EPosition)

Refer to bug for more information.

Original issue's description:
> Web Animations API: Support non-animatable properties being animated via element.animate()
> 
> CSS Animations and Transitions have a select number of properties that
> are allowed to be animated. Web Animations allows for all non-animation
> properties falling back to a default 50% flip interpolation between values.
> This patch adds support to element.animate() for the non-animatable
> non-animation properties.
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=173067

BUG=369519
TBR=alancutter

Review URL: https://codereview.chromium.org/264793020

git-svn-id: svn://svn.chromium.org/blink/trunk@173262 bbb929c8-8fbe-4397-9dbb-9b2b20218538