Revert of Make --dump-render-tree's requestAnimationFrame more real (https://codereview.chromium.org/131973020/)

Reason for revert:
This seems to cause layout test inspector/layer-compositing-reasons.html to timeout on
all platforms. Reverting it locally fixed the timeout.

http://test-results.appspot.com/dashboards/flakiness_dashboard.html#group=%40ToT%20Blink&tests=inspector%2Flayer-compositing-reasons.html

Original issue's description:
> Make --dump-render-tree's requestAnimationFrame more real
> 
> This CL adds a call to layout in --dump-render-tree's fake implementation of
> requestAnimationFrame, which more closely mirrors what the real implementation
> of requestAnimationFrame does. The real implementation is driven by the
> compositor, which doesn't exist when running with --dump-render-tree.
> 
> R=esprehn@chromium.org
> BUG=337617
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=246806

TBR=esprehn@chromium.org,abarth@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=337617

Review URL: https://codereview.chromium.org/145173013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246841 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246841