Disable PLC for iSAC

A codec's packet-loss concealer is called once from NetEq before
decoding the first packet after a packet loss. The purpose is not to
use the PLC output, but to prepare the state of the decoder such that
it may recover faster after the loss. However, this effect is not
achieved by calling iSAC's PLC. Also, there are some problems with the
fixed-point implementation of the PLC (see the associated bug).

BUG=4423
R=kwiberg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/42849004

Cr-Commit-Position: refs/heads/master@{#8827}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8827 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t_impl.h b/webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t_impl.h
index 1bfb416..db30444 100644
--- a/webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t_impl.h
+++ b/webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t_impl.h
@@ -242,7 +242,7 @@
 
 template <typename T>
 bool AudioEncoderDecoderIsacT<T>::HasDecodePlc() const {
-  return true;
+  return false;
 }
 
 template <typename T>
diff --git a/webrtc/modules/audio_coding/main/acm2/audio_coding_module_unittest.cc b/webrtc/modules/audio_coding/main/acm2/audio_coding_module_unittest.cc
index a600129..283595e 100644
--- a/webrtc/modules/audio_coding/main/acm2/audio_coding_module_unittest.cc
+++ b/webrtc/modules/audio_coding/main/acm2/audio_coding_module_unittest.cc
@@ -563,7 +563,7 @@
 TEST_F(AcmReceiverBitExactness, MAYBE_8kHzOutput) {
   Run(8000,
       PlatformChecksum("dcee98c623b147ebe1b40dd30efa896e",
-                       "6ac89c7145072c26bfeba602cd661afb",
+                       "adc92e173f908f93b96ba5844209815a",
                        "908002dc01fc4eb1d2be24eb1d3f354b"));
 }
 
@@ -576,7 +576,7 @@
 TEST_F(AcmReceiverBitExactness, MAYBE_16kHzOutput) {
   Run(16000,
       PlatformChecksum("f790e7a8cce4e2c8b7bb5e0e4c5dac0d",
-                       "3e888eb04f57db2c6ef952fe64f17fe6",
+                       "8cffa6abcb3e18e33b9d857666dff66a",
                        "a909560b5ca49fa472b17b7b277195e9"));
 }
 
@@ -589,7 +589,7 @@
 TEST_F(AcmReceiverBitExactness, MAYBE_32kHzOutput) {
   Run(32000,
       PlatformChecksum("306e0d990ee6e92de3fbecc0123ece37",
-                       "aeca37e963310f5b6552b7edea23c2f1",
+                       "3e126fe894720c3f85edadcc91964ba5",
                        "441aab4b347fb3db4e9244337aca8d8e"));
 }
 
@@ -602,7 +602,7 @@
 TEST_F(AcmReceiverBitExactness, MAYBE_48kHzOutput) {
   Run(48000,
       PlatformChecksum("aa7c232f63a67b2a72703593bdd172e0",
-                       "76b9e99e0a3998aa28355e7a2bd836f7",
+                       "0155665e93067c4e89256b944dd11999",
                        "4ee2730fa1daae755e8a8fd3abd779ec"));
 }
 
diff --git a/webrtc/modules/audio_coding/main/acm2/audio_coding_module_unittest_oldapi.cc b/webrtc/modules/audio_coding/main/acm2/audio_coding_module_unittest_oldapi.cc
index c083f28..81ae8aa 100644
--- a/webrtc/modules/audio_coding/main/acm2/audio_coding_module_unittest_oldapi.cc
+++ b/webrtc/modules/audio_coding/main/acm2/audio_coding_module_unittest_oldapi.cc
@@ -751,7 +751,7 @@
 TEST_F(AcmReceiverBitExactnessOldApi, MAYBE_8kHzOutput) {
   Run(8000,
       PlatformChecksum("dcee98c623b147ebe1b40dd30efa896e",
-                       "6ac89c7145072c26bfeba602cd661afb",
+                       "adc92e173f908f93b96ba5844209815a",
                        "908002dc01fc4eb1d2be24eb1d3f354b"));
 }
 
@@ -764,7 +764,7 @@
 TEST_F(AcmReceiverBitExactnessOldApi, MAYBE_16kHzOutput) {
   Run(16000,
       PlatformChecksum("f790e7a8cce4e2c8b7bb5e0e4c5dac0d",
-                       "3e888eb04f57db2c6ef952fe64f17fe6",
+                       "8cffa6abcb3e18e33b9d857666dff66a",
                        "a909560b5ca49fa472b17b7b277195e9"));
 }
 
@@ -777,7 +777,7 @@
 TEST_F(AcmReceiverBitExactnessOldApi, MAYBE_32kHzOutput) {
   Run(32000,
       PlatformChecksum("306e0d990ee6e92de3fbecc0123ece37",
-                       "aeca37e963310f5b6552b7edea23c2f1",
+                       "3e126fe894720c3f85edadcc91964ba5",
                        "441aab4b347fb3db4e9244337aca8d8e"));
 }
 
@@ -790,7 +790,7 @@
 TEST_F(AcmReceiverBitExactnessOldApi, MAYBE_48kHzOutput) {
   Run(48000,
       PlatformChecksum("aa7c232f63a67b2a72703593bdd172e0",
-                       "76b9e99e0a3998aa28355e7a2bd836f7",
+                       "0155665e93067c4e89256b944dd11999",
                        "4ee2730fa1daae755e8a8fd3abd779ec"));
 }
 
diff --git a/webrtc/modules/audio_coding/neteq/audio_decoder_unittest.cc b/webrtc/modules/audio_coding/neteq/audio_decoder_unittest.cc
index 9f3b0fe..728caef 100644
--- a/webrtc/modules/audio_coding/neteq/audio_decoder_unittest.cc
+++ b/webrtc/modules/audio_coding/neteq/audio_decoder_unittest.cc
@@ -521,8 +521,7 @@
   EXPECT_TRUE(CodecSupported(kDecoderISAC));
   EncodeDecodeTest(0, tolerance, mse, delay);
   ReInitTest();
-  EXPECT_TRUE(decoder_->HasDecodePlc());
-  DecodePlcTest();
+  EXPECT_FALSE(decoder_->HasDecodePlc());
 }
 
 TEST_F(AudioDecoderIsacSwbTest, EncodeDecode) {
@@ -532,8 +531,7 @@
   EXPECT_TRUE(CodecSupported(kDecoderISACswb));
   EncodeDecodeTest(0, tolerance, mse, delay);
   ReInitTest();
-  EXPECT_TRUE(decoder_->HasDecodePlc());
-  DecodePlcTest();
+  EXPECT_FALSE(decoder_->HasDecodePlc());
 }
 
 // Fails Android ARM64. https://code.google.com/p/webrtc/issues/detail?id=4198
@@ -554,8 +552,7 @@
 #endif
   EncodeDecodeTest(kEncodedBytes, tolerance, mse, delay);
   ReInitTest();
-  EXPECT_TRUE(decoder_->HasDecodePlc());
-  DecodePlcTest();
+  EXPECT_FALSE(decoder_->HasDecodePlc());
 }
 
 TEST_F(AudioDecoderG722Test, EncodeDecode) {