Revert of AcmReceiver: Ask NetEq to delete all decoders at once instead of one by one (patchset #2 id:20001 of https://codereview.webrtc.org/2342313002/ )

Reason for revert:
Seems to have broken Chromium tests.

Original issue's description:
> AcmReceiver: Ask NetEq to delete all decoders at once instead of one by one
>
> It requires a new NetEq method, but it can no longer fail. And we no
> longer need to use AcmReceiver::decoders_, which we're trying to
> eliminate.
>
> BUG=webrtc:5801
>
> Committed: https://crrev.com/f6232b43a176e1717354b671a0a52b887d70de59
> Cr-Commit-Position: refs/heads/master@{#14275}

TBR=ossu@webrtc.org,henrik.lundin@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:5801

Review-Url: https://codereview.webrtc.org/2349973002
Cr-Commit-Position: refs/heads/master@{#14278}

webrtc/modules/audio_coding/acm2/acm_receiver.cc

@@ -245,12 +245,27 @@ void AcmReceiver::FlushBuffers() {
   neteq_->FlushBuffers();
 }
 
-void AcmReceiver::RemoveAllCodecs() {
+// If failed in removing one of the codecs, this method continues to remove as
+// many as it can.
+int AcmReceiver::RemoveAllCodecs() {
+  int ret_val = 0;
   rtc::CritScope lock(&crit_sect_);
-  neteq_->RemoveAllPayloadTypes();
-  decoders_.clear();
+  for (auto it = decoders_.begin(); it != decoders_.end(); ) {
+    auto cur = it;
+    ++it;  // it will be valid even if we erase cur
+    if (neteq_->RemovePayloadType(cur->second.payload_type) == 0) {
+      decoders_.erase(cur);
+    } else {
+      LOG_F(LS_ERROR) << "Cannot remove payload "
+                      << static_cast<int>(cur->second.payload_type);
+      ret_val = -1;
+    }
+  }
+
+  // No codec is registered, invalidate last audio decoder.
   last_audio_decoder_ = rtc::Optional<CodecInst>();
   last_packet_sample_rate_hz_ = rtc::Optional<int>();
+  return ret_val;
 }
 
 int AcmReceiver::RemoveCodec(uint8_t payload_type) {

webrtc/modules/audio_coding/acm2/acm_receiver.h

@@ -186,7 +186,7 @@ class AcmReceiver {
   //
   // Remove all registered codecs.
   //
-  void RemoveAllCodecs();
+  int RemoveAllCodecs();
 
   // Returns the RTP timestamp for the last sample delivered by GetAudio().
   // The return value will be empty if no valid timestamp is available.

webrtc/modules/audio_coding/acm2/audio_coding_module.cc

@@ -948,8 +948,10 @@ int AudioCodingModuleImpl::InitializeReceiverSafe() {
   // If the receiver is already initialized then we want to destroy any
   // existing decoders. After a call to this function, we should have a clean
   // start-up.
-  if (receiver_initialized_)
-    receiver_.RemoveAllCodecs();
+  if (receiver_initialized_) {
+    if (receiver_.RemoveAllCodecs() < 0)
+      return -1;
+  }
   receiver_.ResetInitialDelay();
   receiver_.SetMinimumDelay(0);
   receiver_.SetMaximumDelay(0);

webrtc/modules/audio_coding/neteq/decoder_database.cc

@@ -169,12 +169,6 @@ int DecoderDatabase::Remove(uint8_t rtp_payload_type) {
   return kOK;
 }
 
-void DecoderDatabase::RemoveAll() {
-  decoders_.clear();
-  active_decoder_type_ = -1;      // No active decoder.
-  active_cng_decoder_type_ = -1;  // No active CNG decoder.
-}
-
 const DecoderDatabase::DecoderInfo* DecoderDatabase::GetDecoderInfo(
     uint8_t rtp_payload_type) const {
   DecoderMap::const_iterator it = decoders_.find(rtp_payload_type);

webrtc/modules/audio_coding/neteq/decoder_database.h

@@ -136,9 +136,6 @@ class DecoderDatabase {
   // Returns kDecoderNotFound or kOK depending on the outcome of the operation.
   virtual int Remove(uint8_t rtp_payload_type);
 
-  // Remove all entries.
-  void RemoveAll();
-
   // Returns a pointer to the DecoderInfo struct for |rtp_payload_type|. If
   // no decoder is registered with that |rtp_payload_type|, NULL is returned.
   virtual const DecoderInfo* GetDecoderInfo(uint8_t rtp_payload_type) const;

webrtc/modules/audio_coding/neteq/include/neteq.h

@@ -183,9 +183,6 @@ class NetEq {
   // -1 on failure.
   virtual int RemovePayloadType(uint8_t rtp_payload_type) = 0;
 
-  // Removes all payload types from the codec database.
-  virtual void RemoveAllPayloadTypes() = 0;
-
   // Sets a minimum delay in millisecond for packet buffer. The minimum is
   // maintained unless a higher latency is dictated by channel condition.
   // Returns true if the minimum is successfully applied, otherwise false is

webrtc/modules/audio_coding/neteq/neteq_impl.cc

@@ -291,11 +291,6 @@ int NetEqImpl::RemovePayloadType(uint8_t rtp_payload_type) {
   return kFail;
 }
 
-void NetEqImpl::RemoveAllPayloadTypes() {
-  rtc::CritScope lock(&crit_sect_);
-  decoder_database_->RemoveAll();
-}
-
 bool NetEqImpl::SetMinimumDelay(int delay_ms) {
   rtc::CritScope lock(&crit_sect_);
   if (delay_ms >= 0 && delay_ms < 10000) {

webrtc/modules/audio_coding/neteq/neteq_impl.h

@@ -123,8 +123,6 @@ class NetEqImpl : public webrtc::NetEq {
   // -1 on failure.
   int RemovePayloadType(uint8_t rtp_payload_type) override;
 
-  void RemoveAllPayloadTypes() override;
-
   bool SetMinimumDelay(int delay_ms) override;
 
   bool SetMaximumDelay(int delay_ms) override;