Remove APM-internal usage of EchoControlMobile

This is a sibling CL to a similar one for EchoCancellation:
https://webrtc-review.googlesource.com/c/src/+/97603

 - EchoControlMobileImpl will no longer inherit EchoControlMobile.
 - Removes usage of AudioProcessing::echo_control_mobile() inside most of
   the audio processing module and unit tests.

The CL breaks audioproc_f backwards compatibility: It can no longer
use all recorded settings (comfort noise, routing mode), but prints an
error message when unsupported settings are encountered.

Tested: audioproc_f with .wav and aecdump inputs.
Bug: webrtc:9535
Change-Id: I63c3c81bcaf44021315978e1a0f3e42173b988ce
Reviewed-on: https://webrtc-review.googlesource.com/101621
Reviewed-by: Alex Loiko <aleloi@webrtc.org>
Commit-Queue: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24888}
diff --git a/modules/audio_processing/echo_control_mobile_impl.h b/modules/audio_processing/echo_control_mobile_impl.h
index a03ab4d..3341ec5 100644
--- a/modules/audio_processing/echo_control_mobile_impl.h
+++ b/modules/audio_processing/echo_control_mobile_impl.h
@@ -24,21 +24,60 @@
 
 class AudioBuffer;
 
-class EchoControlMobileImpl : public EchoControlMobile {
+class EchoControlMobileImpl {
  public:
   EchoControlMobileImpl(rtc::CriticalSection* crit_render,
                         rtc::CriticalSection* crit_capture);
 
-  ~EchoControlMobileImpl() override;
+  ~EchoControlMobileImpl();
+
+  int Enable(bool enable);
+  bool is_enabled() const;
+
+  // Recommended settings for particular audio routes. In general, the louder
+  // the echo is expected to be, the higher this value should be set. The
+  // preferred setting may vary from device to device.
+  enum RoutingMode {
+    kQuietEarpieceOrHeadset,
+    kEarpiece,
+    kLoudEarpiece,
+    kSpeakerphone,
+    kLoudSpeakerphone
+  };
+
+  // Sets echo control appropriate for the audio routing |mode| on the device.
+  // It can and should be updated during a call if the audio routing changes.
+  int set_routing_mode(RoutingMode mode);
+  RoutingMode routing_mode() const;
+
+  // Comfort noise replaces suppressed background noise to maintain a
+  // consistent signal level.
+  int enable_comfort_noise(bool enable);
+  bool is_comfort_noise_enabled() const;
+
+  // A typical use case is to initialize the component with an echo path from a
+  // previous call. The echo path is retrieved using |GetEchoPath()|, typically
+  // at the end of a call. The data can then be stored for later use as an
+  // initializer before the next call, using |SetEchoPath()|.
+  //
+  // Controlling the echo path this way requires the data |size_bytes| to match
+  // the internal echo path size. This size can be acquired using
+  // |echo_path_size_bytes()|. |SetEchoPath()| causes an entire reset, worth
+  // noting if it is to be called during an ongoing call.
+  //
+  // It is possible that version incompatibilities may result in a stored echo
+  // path of the incorrect size. In this case, the stored path should be
+  // discarded.
+  int SetEchoPath(const void* echo_path, size_t size_bytes);
+  int GetEchoPath(void* echo_path, size_t size_bytes) const;
+
+  // The returned path size is guaranteed not to change for the lifetime of
+  // the application.
+  static size_t echo_path_size_bytes();
 
   void ProcessRenderAudio(rtc::ArrayView<const int16_t> packed_render_audio);
   int ProcessCaptureAudio(AudioBuffer* audio, int stream_delay_ms);
 
-  // EchoControlMobile implementation.
-  bool is_enabled() const override;
-  RoutingMode routing_mode() const override;
-  bool is_comfort_noise_enabled() const override;
-
   void Initialize(int sample_rate_hz,
                   size_t num_reverse_channels,
                   size_t num_output_channels);
@@ -55,13 +94,6 @@
   class Canceller;
   struct StreamProperties;
 
-  // EchoControlMobile implementation.
-  int Enable(bool enable) override;
-  int set_routing_mode(RoutingMode mode) override;
-  int enable_comfort_noise(bool enable) override;
-  int SetEchoPath(const void* echo_path, size_t size_bytes) override;
-  int GetEchoPath(void* echo_path, size_t size_bytes) const override;
-
   int Configure();
 
   rtc::CriticalSection* const crit_render_ RTC_ACQUIRED_BEFORE(crit_capture_);