Adjust svg/animations/animate-linear-discrete-additive*.svg

In these tests we want to sample animation values at a certain point in
time. We are however sampling the animations at the next frame that is
painted - at which point the timeline may have advanced, and hence we
sample at t+<framedelay> (or thereabout) instead. Currently this works
"fine" because the first animation frame follows special scheduling
rules, making sure the timeline won't advance within this time window.
Rather than relying on this, just pause the timeline instead.

BUG=726362

Change-Id: I2314b435861050fd0163670928318563bd09f271
Reviewed-on: https://chromium-review.googlesource.com/563624
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#485166}
3 files changed