This CL adds a queue for pending QualityScalerQpUsageHandlerCallbacks
and private methods for "Queueing", "Handling" and "Aborting" them,
using a sequence number as an ID to ensure we don't accidentally invoke
the same callback twice.
Because we don't have the adaptation task queue yet, callbacks are still
synchronously handled, which means the "pending callbacks" queue would
never have more than 1 element. However, when the adaptation task queue
is added and this is made asynchronous, it will be possible for multiple
callbacks to be pending simultaneously. This design is future-proof.
This CL is split out to aid reviewability. The CL that adds the
adaptation task queue will affect a lot of code. By landing this
separately, the adaptation queue CL will be easier to review.
This CL adds quality_scaler_resource_unittest.cc.
Bug: webrtc:11542, webrtc:11520
Change-Id: I00e7f6bfda9f8e8e82ec25916aa48e9349c8d70c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/174802
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Evan Shrubsole <eshr@google.com>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31219}
9438ddc9fc