Migrate hybrid rotation animation with shell transition

This makes commit 1a7dc4c support shell transition for the
case of display rotation with CHANGE type transition. To
reduce the latency of rotation animation by not waiting
for some insignificant windows.

An example:
1. Rotation changed, request change transition.
2. Collect the windows that don't need to be synced with
   transition into fade controller (the windows still
   have state SYNC_STATE_WAITING_FOR_DRAW) and create
   animation leash for them. Assume there are X and Y.
3. Start transition, that collects visible task and visible
   non-app window tokens which won't be handled by the
   fade controller.
4. The participated windows are drawn, so onTransactionReady
   is called and send the start transaction to shell.
5. X reported drawn. But because the start transaction
   has not committed, postpone to execute the animation.
   Otherwise the fade-in animation shows before rotation
   animation that will look flickering.
6. Shell applies the start transaction, which includes
   - Merged sync transaction (includes X,Y).
   - Show rotation layer (screenshot).
   - Hide the leash of X,Y (It is usually covered
     by screenshot, just in case to ensure smooth fade-in).
7. The commit callback of start transaction is called.
   Start to fade in X (It is usually unobservable because
   rotation animation is also running).
8. The rotation animation finished (finishTransition).
9. Y is really slow and finished now. Fade in it directly.
   This fade animation will be observable.

Bug: 206487939
Test: TransitionTests#testDisplayRotationChange
      DisplayContentTests#testHybridRotationAnimation
Change-Id: If4635abc7ef57cac8a925d9613d988ef3ade62b7

0 files changed, 0 insertions, 0 deletions