Previously, FrameProcessor never had the usecase in which the output surface
is replaced, while previewing introduced this usecase.
When switching output surfaces, we need to destroy the EGL Surface linked to the
surface that is being swapped out, because an EGL surface is linked to the EGL
display (which is not destroyed even when releasing FrameProcessor).
A GL exception will be thrown in the following scenario if we don't destroy the
EGL surface:
1. Creates a Surface, the surface is identified by address 0x11
2. Sets Surface(0x11) on FrameProcessor. Eventually an EGL surface is created
to wrap Surface(0x11)
3. Release FrameProcess, this releases the EGL context
4. Instantiate a new FrameProcessor, sets Surface(0x11) as the output
5. When FrameProcessor creates an EGL surface to wrap Surface(0x11), GL throws
an exception, becasue Surface(0x11) has previouly been connected to an EGL
surface.
PiperOrigin-RevId: 489590072
`availableFrameCount` tracks the number of frames that is avilable on the
`SurfaceTexture`, but haven't been used (by `updateTexImage()`) yet. Thus
semantically this counter should only be decremented after calling
`updateTexImage()`, not before it.
Also reworded `getPendingFrameCount()` javadoc, "external texture" is an
internal state that is not publicised anywhere.
PiperOrigin-RevId: 488765174
Public methods may only refer to public types in their signature. This
change ensures that by switching to a public supertype everywhere.
PiperOrigin-RevId: 485568625
Make it easier to support use of RGBA_101012 rather than RGBA_8888 for EGL
contexts, displays, and surfaces.
This tangentially supports adding HDR tests, by slightly simplifying the color
selection logic we'd have to add in HDR tests.
PiperOrigin-RevId: 482219428
