This CL removes most of the global frame state in VideoProcessor and
replaces that with a vector of frame states. This is useful for pipelining
codecs, where the encoded/decoded frame may not be immediately outputted
after it has been sent to the codec.
The callers (VideoProcessorIntegrationTest and video_quality_measurement)
still call VideoProcessor in a sequential fashion. A follow-up CL will be
submitted that enables batch mode in VideoProcessorIntegrationTest.
Note that VideoProcessor is still not thread safe. Currently, we can run
fairly well on Android due to the synchronicity of our MediaCodec wrapper,
but we still cannot run on iOS due to async issues. This will be fixed in
the future.
BUG=webrtc:6634
Review-Url: https://codereview.webrtc.org/2711133002
Cr-Commit-Position: refs/heads/master@{#17084}
17b958c041