Revert of Implement /content/ combinator. (https://codereview.chromium.org/187353003/)

Reason for revert:
Shadow DOM styling spec was changed.
/content/ was reverted in the spec.

Original issue's description:
> Implement /content/ combinator.
> 
> spec: shadow styling
> http://dev.w3.org/csswg/shadow-styling/#content-combinator
> 
> The added layout tests are basically the same as ::content's, because /content/ combinator should have almost the same behavior (except css text, ::content with descendant combinator).
> 
> BUG=349334
> TEST=fast/dom/shadow/cascade-of-treeboundary-crossing-rules.html,fast/dom/shadow/content-combinator-css-text.html,fast/dom/shadow/content-combinator-dynamic-attribute-change.html,fast/dom/shadow/content-combinator-in-inert-shadow.html,fast/dom/shadow/content-combinator-scoped.html,fast/dom/shadow/content-combinator-with-cat.html,fast/dom/shadow/content-combinator-with-hat.html,fast/dom/shadow/content-combinator-with-host-pseudo-class-2.html,fast/dom/shadow/content-combinator-with-host-pseudo-class.html,fast/dom/shadow/content-combinator.html,fast/dom/shadow/multiple-content-combinator.html,fast/dom/shadow/no-style-sharing-with-uncommon-attribute-and-content-combinator.html
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169085

BUG=349334
TBR=dglazkov@chromium.org,hayato@chromium.org

Review URL: https://codereview.chromium.org/205563004

git-svn-id: svn://svn.chromium.org/blink/trunk@169822 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Oilpan: Move AnimatableValue's hierarchy to oilpan's heap

This CL is doing mechanical replacement and there's nothing non-trivial.

BUG=340522

Review URL: https://codereview.chromium.org/204743002

git-svn-id: svn://svn.chromium.org/blink/trunk@169823 bbb929c8-8fbe-4397-9dbb-9b2b20218538