Add AudioReceiveStream::SetGain() method and use that in WVoMC::SetOutputVolume().

webrtc/media/engine/webrtcvoiceengine_unittest.cc

 /*
  *  Copyright (c) 2008 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 3121 matching lines @@
   int channel_id2 = voe_.GetLastChannel();
   EXPECT_EQ(channel_id2, media_channel->GetSendChannelId(kSsrc2));
 }
 
 TEST_F(WebRtcVoiceEngineTestFake, SetOutputVolume) {
   EXPECT_TRUE(SetupChannel());
   EXPECT_FALSE(channel_->SetOutputVolume(kSsrc2, 0.5));
   cricket::StreamParams stream;
   stream.ssrcs.push_back(kSsrc2);
   EXPECT_TRUE(channel_->AddRecvStream(stream));
-  int channel_id = voe_.GetLastChannel();
   EXPECT_TRUE(channel_->SetOutputVolume(kSsrc2, 3));
-  float scale = 0;
-  EXPECT_EQ(0, voe_.GetChannelOutputVolumeScaling(channel_id, scale));
-  EXPECT_DOUBLE_EQ(3, scale);
+  EXPECT_DOUBLE_EQ(3, GetRecvStream(kSsrc2).gain());

[kwiberg-webrtc, 2016/06/16 09:26:53]

Add an EXPECT_ to test the value of .gain() before the volume has been set?

[the sun, 2016/06/16 14:34:06]

Done.

 }
 
 TEST_F(WebRtcVoiceEngineTestFake, SetOutputVolumeDefaultRecvStream) {
   EXPECT_TRUE(SetupChannel());
   EXPECT_TRUE(channel_->SetOutputVolume(0, 2));
   DeliverPacket(kPcmuFrame, sizeof(kPcmuFrame));
-  int channel_id = voe_.GetLastChannel();
-  float scale = 0;
-  EXPECT_EQ(0, voe_.GetChannelOutputVolumeScaling(channel_id, scale));
-  EXPECT_DOUBLE_EQ(2, scale);
+  EXPECT_DOUBLE_EQ(2, GetRecvStream(1).gain());
   EXPECT_TRUE(channel_->SetOutputVolume(0, 3));
-  EXPECT_EQ(0, voe_.GetChannelOutputVolumeScaling(channel_id, scale));
-  EXPECT_DOUBLE_EQ(3, scale);
+  EXPECT_DOUBLE_EQ(3, GetRecvStream(1).gain());
 }
 
 TEST_F(WebRtcVoiceEngineTestFake, SetsSyncGroupFromSyncLabel) {
   const uint32_t kAudioSsrc = 123;
   const std::string kSyncLabel = "AvSyncLabel";
 
   EXPECT_TRUE(SetupSendStream());
   cricket::StreamParams sp = cricket::StreamParams::CreateLegacy(kAudioSsrc);
   sp.sync_label = kSyncLabel;
   // Creating two channels to make sure that sync label is set properly for both
@@ skipping 363 matching lines @@
   cricket::WebRtcVoiceEngine engine(
       nullptr, webrtc::CreateBuiltinAudioDecoderFactory());
   std::unique_ptr<webrtc::Call> call(
       webrtc::Call::Create(webrtc::Call::Config()));
   cricket::WebRtcVoiceMediaChannel channel(&engine, cricket::MediaConfig(),
                                            cricket::AudioOptions(), call.get());
   cricket::AudioRecvParameters parameters;
   parameters.codecs = engine.recv_codecs();
   EXPECT_TRUE(channel.SetRecvParameters(parameters));
 }