Limit seamless rotation to TRANSFORM_INVERSE_DISPLAY children.

In what can only be called an unfortunate workaround we require
seamlessly rotated child windows to have the
TRANSFORM_TO_DISPLAY_INVERSE
flag. Due to limitations in the client API, there is no way for the
client to set this flag in a race free fashion. If we seamlessly rotate
a window which does not have this flag, but then it gains it,
we will have an incorrect visual result (rotated buffer contents). This
means if we want to support seamlessly rotating windows which could gain
this flag, we can't seamlessly rotate windows which don't have it. This
unfortunately limits seamless rotation in N to Camera framework users,
native code, and applications without child windows. This is unfortunate
but having the camera work was always our primary use case, and it's not
as if we are offering an API for it, it's a behind the scenes
enhancement of ROTATION_ANIMATION_JUMPCUT.

Bug: 30171992
Change-Id: I082e323ee569cfc1ff2559657cc22194c251c7ec
1 file changed