There are two difficulties to apply render surface in screen rotation animation:

1. There is no need to create render surface in the screen rotation animation. Therefore, create a render surface to cache might be a regression.

2. The animation is implemented by Update opacity and transform from SetYYYYYYFromAnimation. Currently this will invalidate the cache.
https://cs.chromium.org/chromium/src/ash/rotator/screen_rotation_animation.cc?l=52&rcl=3b0c53b9487ec33ae93f8f6c071c64f936d97f06

I and ajuma@ discussed offline about two possible solutions:

1. Maybe a short term solution, modify the screen rotation animation so that we can use cc::Animation, not using SetYYYYYYFromAnimation. ajuma@ pointed out this will not make the animation faster. But we can reuse the cache by this modification because it will not invalidate the render surface cache in current code.

2. For long term solution, to create a better mechanism to identify the damage source, from cc::Animation or UI animation. Any damage from cc::Animation might be ok not to invalidate the cache.
https://bugs.chromium.org/p/chromium/issues/detail?id=755828

We may not want this feature soon. Close for now.