Avoid setting timers from SVGImage::resetAnimation()

When resetting the timeline to t=0, we may up generating syncbase
notification, which sets up a timer (to update any possibly dependent
intervals.) Since resetAnimation() is what's called when the (SVG)Image
no longer has any clients, we should try to make sure it is indeed
idle after that happens. This avoids trying to update animation state
while the image is otherwise dead, leaving "reactivation" to the time
it is next painted.

BUG=627418

Review-Url: https://codereview.chromium.org/2247783003
Cr-Commit-Position: refs/heads/master@{#412798}
2 files changed