Modifying the view size can cause TSR history to allocate large amount of memory

When animating the split fraction of a splitscreen experience, TSR causes an significant increase in UAV memory.

In PIX, this appears to be caused by TSR allocating the history multiple times when the view resizes.

1. Create a animating view split for a splitscreen view.
2. Animate the view at runtime
3. Run stat gpu
4. The resize of the views causes UAV texture memory to climb

Alternatively, I believe this is also reproducible by rapidly resizing the viewport in editor. This may not be the same issue, however.

Expected: UAV memory to increase slightly as seen with TAA.
Actual: At HistoryPercentage 200, the animated view split leads to an almost 1600MiB increase in UAV texture memory, from 1900MiB to ~3400-3500MiB.