In bug 1762424 we introduced a rendering path on Android using the
SurfaceControl API, in order to work around a bug preventing recovery
from a GPU process crash. However, the initial implementation caused
this bug: repeatedly sending the same SurfaceControl objects over AIDL
to the GPU process resulted in them being leaked, eventually causing
severe display issues. Not only were we duplicating the SurfaceControl
for each widget, but each time a widget was resized too.
This patch reworks our usage of the SurfaceControl API to avoid ever
having to send them cross-process. Instead, we create a single child
SurfaceControl object for each SurfaceControl that is attached to a
widget. (Typically there will be a single one shared between all
widgets, changing only when the app is paused and resumed, which is
much fewer than one per widget per resize.)
In the parent process we obtain the Surfaces that will be rendered in
to from the child SurfaceControls, and only send those Surfaces to the
GPU process. Thankfully unlike SurfaceControls, sending Surfaces
cross-process does not cause leaks. When the GPU process dies we
simply destroy all of the child SurfaceControls, and recreate them
again on-demand.
Differential Revision: https://phabricator.services.mozilla.com/D147437
2cf59fe695