Reland "NetEq: Deprecate playout modes Fax, Off and Streaming"

This is a reland of 80c4cca4915dbc6094a5bfae749f85f7371eadd1

Original change's description:
> NetEq: Deprecate playout modes Fax, Off and Streaming
> 
> The playout modes other than Normal have not been reachable for a long
> time, other than through tests. It is time to deprecate them.
> 
> The only meaningful use was that Fax mode was sometimes set from
> tests, in order to avoid time-stretching operations (accelerate and
> pre-emptive expand) from messing with the test results. With this CL,
> a new config is added instead, which lets the user specify exactly
> this: don't do time-stretching.
> 
> As a result of Fax and Off modes being removed, the following code
> clean-up was done:
> - Fold DecisionLogicNormal into DecisionLogic.
> - Remove AudioRepetition and AlternativePlc operations, since they can
>   no longer be reached.
> 
> Bug: webrtc:9421
> Change-Id: I651458e9c1931a99f3b07e242817d303bac119df
> Reviewed-on: https://webrtc-review.googlesource.com/84123
> Commit-Queue: Henrik Lundin <henrik.lundin@webrtc.org>
> Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
> Reviewed-by: Minyue Li <minyue@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#23704}

Bug: webrtc:9421
Change-Id: Ice351b635788167f2971b26470f73a5e5fa1a240
Reviewed-on: https://webrtc-review.googlesource.com/86543
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Commit-Queue: Henrik Lundin <henrik.lundin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23799}
diff --git a/modules/audio_coding/neteq/tools/neteq_input.h b/modules/audio_coding/neteq/tools/neteq_input.h
index 5e2cbd2..a13a86e 100644
--- a/modules/audio_coding/neteq/tools/neteq_input.h
+++ b/modules/audio_coding/neteq/tools/neteq_input.h
@@ -78,6 +78,28 @@
   virtual absl::optional<RTPHeader> NextHeader() const = 0;
 };
 
+// Wrapper class to impose a time limit on a NetEqInput object, typically
+// another time limit than what the object itself provides. For example, an
+// input taken from a file can be cut shorter by wrapping it in this class.
+class TimeLimitedNetEqInput : public NetEqInput {
+ public:
+  TimeLimitedNetEqInput(std::unique_ptr<NetEqInput> input, int64_t duration_ms);
+  rtc::Optional<int64_t> NextPacketTime() const override;
+  rtc::Optional<int64_t> NextOutputEventTime() const override;
+  std::unique_ptr<PacketData> PopPacket() override;
+  void AdvanceOutputEvent() override;
+  bool ended() const override;
+  rtc::Optional<RTPHeader> NextHeader() const override;
+
+ private:
+  void MaybeSetEnded();
+
+  std::unique_ptr<NetEqInput> input_;
+  const rtc::Optional<int64_t> start_time_ms_;
+  const int64_t duration_ms_;
+  bool ended_ = false;
+};
+
 }  // namespace test
 }  // namespace webrtc
 #endif  // MODULES_AUDIO_CODING_NETEQ_TOOLS_NETEQ_INPUT_H_