Avoid multiply-by-infinity (which is UB) in another case.

Bug: 1116289
Change-Id: If301c1bbac0ab64e06b9e23337a530033217e7b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2376506
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Robert Flack <flackr@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801789}

cc/animation/keyframe_model.cc

@@ -286,14 +286,16 @@ base::TimeDelta KeyframeModel::TrimTimeToCurrentIteration(
   if (curve_->Duration() <= base::TimeDelta())
     return base::TimeDelta();
 
-  base::TimeDelta repeated_duration = curve_->Duration() * iterations_;
-  base::TimeDelta active_duration =
-      repeated_duration / std::abs(playback_rate_);
+  base::TimeDelta repeated_duration = std::isfinite(iterations_)
+                                          ? (curve_->Duration() * iterations_)
+                                          : base::TimeDelta::Max();
 
   // Calculate the scaled active time
   base::TimeDelta scaled_active_time;
   if (playback_rate_ < 0) {
     DCHECK(std::isfinite(iterations_));
+    base::TimeDelta active_duration =
+        repeated_duration / std::abs(playback_rate_);
     scaled_active_time =
         ((active_time - active_duration) * playback_rate_) + start_offset;
   } else {