Don't forget to support G722 stereo decoding

webrtc/api/audio_codecs/test/audio_decoder_factory_template_unittest.cc

 /*
  *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 101 matching lines @@
 }
 
 TEST(AudioDecoderFactoryTemplateTest, G722) {
   auto factory = CreateAudioDecoderFactory<AudioDecoderG722>();
   EXPECT_THAT(factory->GetSupportedDecoders(),
               testing::ElementsAre(
                   AudioCodecSpec{{"g722", 8000, 1}, {16000, 1, 64000}}));
   EXPECT_FALSE(factory->IsSupportedDecoder({"foo", 8000, 1}));
   EXPECT_TRUE(factory->IsSupportedDecoder({"g722", 8000, 1}));
   EXPECT_EQ(nullptr, factory->MakeAudioDecoder({"bar", 16000, 1}));
-  auto dec = factory->MakeAudioDecoder({"g722", 8000, 1});
-  ASSERT_NE(nullptr, dec);
-  EXPECT_EQ(16000, dec->SampleRateHz());
+  auto dec1 = factory->MakeAudioDecoder({"g722", 8000, 1});
+  ASSERT_NE(nullptr, dec1);
+  EXPECT_EQ(16000, dec1->SampleRateHz());
+  EXPECT_EQ(1u, dec1->Channels());
+  auto dec2 = factory->MakeAudioDecoder({"g722", 8000, 2});
+  ASSERT_NE(nullptr, dec2);
+  EXPECT_EQ(16000, dec2->SampleRateHz());
+  EXPECT_EQ(2u, dec2->Channels());
+  auto dec3 = factory->MakeAudioDecoder({"g722", 8000, 3});
+  ASSERT_EQ(nullptr, dec3);
 }
 
 }  // namespace webrtc