CSS Animations: Animations should start immediately when the page is not visible

In r67865[1] the starting of CSS animations and transitions was deferred
until the next compositing update. This introduced a regression where
animations triggered on a page which is not visible would not start
until the page was made visible again.

This patch allows animations to start immediately when a page is not visible.

[1] https://src.chromium.org/viewvc/blink?view=rev&revision=167865

BUG=350892

Review URL: https://codereview.chromium.org/225093015

git-svn-id: svn://svn.chromium.org/blink/trunk@171021 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove [LegacyTreatAsPartialInterface] from SVGZoomAndPan

implemented SVG interfaces: 1/5

This has a good example of the problems using static member functions
for implemented interfaces causes: this fixes a hierarchy violation
where interface and implementation for derived class SVGViewSpec
is defined in the base class SVGZoomAndPan !

R=haraken
BUG=360435

Review URL: https://codereview.chromium.org/227043008

git-svn-id: svn://svn.chromium.org/blink/trunk@171022 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove [LegacyTreatAsPartialInterface] from SVGTests

Also:
* Remove SVG 1.1 cruft:
SVGUseElement implements SVGTests;

...since implemented by parent:
interface SVGUseElement : SVGGraphicsElement { ... };
SVGGraphicsElement implements SVGTests;

R=haraken
BUG=360435

Review URL: https://codereview.chromium.org/226623010

git-svn-id: svn://svn.chromium.org/blink/trunk@171023 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Web animations: Adds new getAnimatableValue method to Keyframe and removes CompositorAnimations dependency on AnimatableValueKeyframe by using this method instead.

BUG=360471

Review URL: https://codereview.chromium.org/228043002

git-svn-id: svn://svn.chromium.org/blink/trunk@171024 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Enable Media condition parsing on the MQ parser

Enable the MediaQueryParser to also parse media conditions on top of full media query sets.
That is in preparation for the sizes attribute parser, that will use that functionality.

BUG=357586

Review URL: https://codereview.chromium.org/223643002

git-svn-id: svn://svn.chromium.org/blink/trunk@171025 bbb929c8-8fbe-4397-9dbb-9b2b20218538