Revert "Reporting of decoding_codec_plc events"

This reverts commit 0a88ea050cda58de81d624cf2764d46929447ed5.

Reason for revert: This CL breaks Chromium's FYI bots (example: https://ci.chromium.org/p/chromium/builders/webrtc.fyi/WebRTC%20Chromium%20FYI%20Linux%20Tester/4033).

Original change's description:
> Reporting of decoding_codec_plc events
> 
> Change-Id: Id71b37244bc98bffaf25131a519127b3d2b86a8f
> 
> Bug: webrtc:10838
> Change-Id: Id71b37244bc98bffaf25131a519127b3d2b86a8f
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/147263
> Commit-Queue: Alex Narest <alexnarest@google.com>
> Reviewed-by: Magnus Flodman <mflodman@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#28700}

TBR=mflodman@webrtc.org,alexnarest@google.com

Change-Id: I5e5dd29ee375ba422f79932d4b8c3fd028a53db4
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:10838
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/147269
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28707}
diff --git a/modules/audio_coding/acm2/audio_coding_module_unittest.cc b/modules/audio_coding/acm2/audio_coding_module_unittest.cc
index e621f40..ffa2bdc 100644
--- a/modules/audio_coding/acm2/audio_coding_module_unittest.cc
+++ b/modules/audio_coding/acm2/audio_coding_module_unittest.cc
@@ -266,7 +266,7 @@
   EXPECT_EQ(0, stats.calls_to_silence_generator);
   EXPECT_EQ(0, stats.decoded_normal);
   EXPECT_EQ(0, stats.decoded_cng);
-  EXPECT_EQ(0, stats.decoded_neteq_plc);
+  EXPECT_EQ(0, stats.decoded_plc);
   EXPECT_EQ(0, stats.decoded_plc_cng);
   EXPECT_EQ(0, stats.decoded_muted_output);
 }
@@ -292,7 +292,7 @@
   EXPECT_EQ(0, stats.calls_to_silence_generator);
   EXPECT_EQ(kNumNormalCalls, stats.decoded_normal);
   EXPECT_EQ(0, stats.decoded_cng);
-  EXPECT_EQ(0, stats.decoded_neteq_plc);
+  EXPECT_EQ(0, stats.decoded_plc);
   EXPECT_EQ(0, stats.decoded_plc_cng);
   EXPECT_EQ(0, stats.decoded_muted_output);
 
@@ -308,7 +308,7 @@
   EXPECT_EQ(0, stats.calls_to_silence_generator);
   EXPECT_EQ(kNumNormalCalls, stats.decoded_normal);
   EXPECT_EQ(0, stats.decoded_cng);
-  EXPECT_EQ(kNumPlc, stats.decoded_neteq_plc);
+  EXPECT_EQ(kNumPlc, stats.decoded_plc);
   EXPECT_EQ(kNumPlcCng, stats.decoded_plc_cng);
   EXPECT_EQ(0, stats.decoded_muted_output);
   // TODO(henrik.lundin) Add a test with muted state enabled.
diff --git a/modules/audio_coding/acm2/call_statistics.cc b/modules/audio_coding/acm2/call_statistics.cc
index e97e529..a506ead 100644
--- a/modules/audio_coding/acm2/call_statistics.cc
+++ b/modules/audio_coding/acm2/call_statistics.cc
@@ -28,11 +28,7 @@
       break;
     }
     case AudioFrame::kPLC: {
-      ++decoding_stat_.decoded_neteq_plc;
-      break;
-    }
-    case AudioFrame::kCodecPLC: {
-      ++decoding_stat_.decoded_codec_plc;
+      ++decoding_stat_.decoded_plc;
       break;
     }
     case AudioFrame::kCNG: {
diff --git a/modules/audio_coding/acm2/call_statistics_unittest.cc b/modules/audio_coding/acm2/call_statistics_unittest.cc
index b96977b..d7ac953 100644
--- a/modules/audio_coding/acm2/call_statistics_unittest.cc
+++ b/modules/audio_coding/acm2/call_statistics_unittest.cc
@@ -25,7 +25,7 @@
   EXPECT_EQ(0, stats.calls_to_silence_generator);
   EXPECT_EQ(0, stats.decoded_normal);
   EXPECT_EQ(0, stats.decoded_cng);
-  EXPECT_EQ(0, stats.decoded_neteq_plc);
+  EXPECT_EQ(0, stats.decoded_plc);
   EXPECT_EQ(0, stats.decoded_plc_cng);
   EXPECT_EQ(0, stats.decoded_muted_output);
 }
@@ -37,17 +37,15 @@
   call_stats.DecodedBySilenceGenerator();
   call_stats.DecodedByNetEq(AudioFrame::kNormalSpeech, false);
   call_stats.DecodedByNetEq(AudioFrame::kPLC, false);
-  call_stats.DecodedByNetEq(AudioFrame::kCodecPLC, false);
   call_stats.DecodedByNetEq(AudioFrame::kPLCCNG, true);  // Let this be muted.
   call_stats.DecodedByNetEq(AudioFrame::kCNG, false);
 
   stats = call_stats.GetDecodingStatistics();
-  EXPECT_EQ(5, stats.calls_to_neteq);
+  EXPECT_EQ(4, stats.calls_to_neteq);
   EXPECT_EQ(1, stats.calls_to_silence_generator);
   EXPECT_EQ(1, stats.decoded_normal);
   EXPECT_EQ(1, stats.decoded_cng);
-  EXPECT_EQ(1, stats.decoded_neteq_plc);
-  EXPECT_EQ(1, stats.decoded_codec_plc);
+  EXPECT_EQ(1, stats.decoded_plc);
   EXPECT_EQ(1, stats.decoded_plc_cng);
   EXPECT_EQ(1, stats.decoded_muted_output);
 }
diff --git a/modules/audio_coding/include/audio_coding_module_typedefs.h b/modules/audio_coding/include/audio_coding_module_typedefs.h
index 95314a3..d256fd1 100644
--- a/modules/audio_coding/include/audio_coding_module_typedefs.h
+++ b/modules/audio_coding/include/audio_coding_module_typedefs.h
@@ -57,8 +57,7 @@
       : calls_to_silence_generator(0),
         calls_to_neteq(0),
         decoded_normal(0),
-        decoded_neteq_plc(0),
-        decoded_codec_plc(0),
+        decoded_plc(0),
         decoded_cng(0),
         decoded_plc_cng(0),
         decoded_muted_output(0) {}
@@ -67,8 +66,7 @@
                                    // and NetEq was disengaged from decoding.
   int calls_to_neteq;              // Number of calls to NetEq.
   int decoded_normal;  // Number of calls where audio RTP packet decoded.
-  int decoded_neteq_plc;  // Number of calls resulted in NetEq PLC.
-  int decoded_codec_plc;  // Number of calls resulted in codec PLC.
+  int decoded_plc;     // Number of calls resulted in PLC.
   int decoded_cng;  // Number of calls where comfort noise generated due to DTX.
   int decoded_plc_cng;       // Number of calls resulted where PLC faded to CNG.
   int decoded_muted_output;  // Number of calls returning a muted state output.
diff --git a/modules/audio_coding/neteq/neteq_impl.cc b/modules/audio_coding/neteq/neteq_impl.cc
index 5466409..8ef08ce 100644
--- a/modules/audio_coding/neteq/neteq_impl.cc
+++ b/modules/audio_coding/neteq/neteq_impl.cc
@@ -203,11 +203,6 @@
       audio_frame->vad_activity_ = AudioFrame::kVadPassive;
       break;
     }
-    case NetEqImpl::OutputType::kCodecPLC: {
-      audio_frame->speech_type_ = AudioFrame::kCodecPLC;
-      audio_frame->vad_activity_ = last_vad_activity;
-      break;
-    }
     default:
       RTC_NOTREACHED();
   }
@@ -2093,8 +2088,6 @@
     return OutputType::kPLC;
   } else if (vad_->running() && !vad_->active_speech()) {
     return OutputType::kVadPassive;
-  } else if (last_mode_ == kModeCodecPlc) {
-    return OutputType::kCodecPLC;
   } else {
     return OutputType::kNormalSpeech;
   }
diff --git a/modules/audio_coding/neteq/neteq_impl.h b/modules/audio_coding/neteq/neteq_impl.h
index c4887a7..9e1af10 100644
--- a/modules/audio_coding/neteq/neteq_impl.h
+++ b/modules/audio_coding/neteq/neteq_impl.h
@@ -64,14 +64,7 @@
 
 class NetEqImpl : public webrtc::NetEq {
  public:
-  enum class OutputType {
-    kNormalSpeech,
-    kPLC,
-    kCNG,
-    kPLCCNG,
-    kVadPassive,
-    kCodecPLC
-  };
+  enum class OutputType { kNormalSpeech, kPLC, kCNG, kPLCCNG, kVadPassive };
 
   enum ErrorCodes {
     kNoError = 0,