Revert "Remove APM-internal usage of EchoControlMobile"

This reverts commit 2fbb83b16b4c2c1712cbe898ca3ba42d6da3e96f.

Reason for revert: Speculative revert over failing Chromium bot:
https://ci.chromium.org/p/chromium/builders/luci.chromium.webrtc.fyi/WebRTC%20Chromium%20FYI%20Android%20Tests%20%28dbg%29%20%28M%20Nexus5X%29/117

Original change's description:
> 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}

TBR=saza@webrtc.org,aleloi@webrtc.org

Change-Id: I1f8a27ac291f2cdc16c8daa32e399b74d489dbb9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:9535
Reviewed-on: https://webrtc-review.googlesource.com/102642
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Commit-Queue: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24895}
diff --git a/modules/audio_processing/echo_control_mobile_impl.cc b/modules/audio_processing/echo_control_mobile_impl.cc
index bd125c6..272da7a 100644
--- a/modules/audio_processing/echo_control_mobile_impl.cc
+++ b/modules/audio_processing/echo_control_mobile_impl.cc
@@ -20,17 +20,17 @@
 namespace webrtc {
 
 namespace {
-int16_t MapSetting(EchoControlMobileImpl::RoutingMode mode) {
+int16_t MapSetting(EchoControlMobile::RoutingMode mode) {
   switch (mode) {
-    case EchoControlMobileImpl::kQuietEarpieceOrHeadset:
+    case EchoControlMobile::kQuietEarpieceOrHeadset:
       return 0;
-    case EchoControlMobileImpl::kEarpiece:
+    case EchoControlMobile::kEarpiece:
       return 1;
-    case EchoControlMobileImpl::kLoudEarpiece:
+    case EchoControlMobile::kLoudEarpiece:
       return 2;
-    case EchoControlMobileImpl::kSpeakerphone:
+    case EchoControlMobile::kSpeakerphone:
       return 3;
-    case EchoControlMobileImpl::kLoudSpeakerphone:
+    case EchoControlMobile::kLoudSpeakerphone:
       return 4;
   }
   RTC_NOTREACHED();
@@ -55,7 +55,7 @@
 }
 }  // namespace
 
-size_t EchoControlMobileImpl::echo_path_size_bytes() {
+size_t EchoControlMobile::echo_path_size_bytes() {
   return WebRtcAecm_echo_path_size_bytes();
 }
 
@@ -268,7 +268,7 @@
   return Configure();
 }
 
-EchoControlMobileImpl::RoutingMode EchoControlMobileImpl::routing_mode() const {
+EchoControlMobile::RoutingMode EchoControlMobileImpl::routing_mode() const {
   rtc::CritScope cs(crit_capture_);
   return routing_mode_;
 }