Pause SVG animations when the document is detached.

Pause SVG animations when the document is detached.

This patch pauses SVG animations if the document is detached or
disposed (matching m_scriptedAnimationController's behavior). SVG 
animations will already reset when the document is re-attached so there
are no additional unpause() calls.

This patch allows us add an assert for document()->frame() in
StyleResolver::styleForElement. No new tests as this functionality is
covered with existing tests and the new assert.

BUG=260966
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=154382

[eseidel, 2013-07-17 05:56:36]

lgtm.

There branch in defaultStyleForElement which only exists to support this
behavior as well.  If you'd like to remove that now, great, otherwise I'll get
it (and all the other places we check !documentSettings() or
!document()->frame() once this lands. :)

[eseidel, 2013-07-17 05:57:46]

I wonder if there are pathways involving less custom code which svg animations
could sign up for.

[pdr., 2013-07-17 06:00:44]

On 2013/07/17 05:56:36, eseidel wrote:
> lgtm.
> 
> There branch in defaultStyleForElement which only exists to support this
> behavior as well.  If you'd like to remove that now, great, otherwise I'll get
> it (and all the other places we check !documentSettings() or
> !document()->frame() once this lands. :)

Good catch. I'll reupload with that change. Lets wait for the debug layout bots
to run before CQ'ing (I only ran a subset of the suite).

> I wonder if there are pathways involving less custom code which svg animations
> could sign up for.

I hope that pathway is Web Animations (and depcreating SMIL :)
I don't have everyone on board with that ideal, but I added a UseCounter to the
SMIL code yesterday to see if I can get them on the ship.

[commit-bot: I haz the power, 2013-07-17 07:06:05]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pdr@chromium.org/19525002/8001

[commit-bot: I haz the power, 2013-07-17 08:53:26]

Change committed as 154382