[chromecast] Slew stream volume changes in StreamMixerAlsa.

chromecast/media/cma/backend/alsa/stream_mixer_alsa_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chromecast/media/cma/backend/alsa/stream_mixer_alsa.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 #include <utility>
@@ skipping 125 matching lines @@
         testing::Invoke(this, &MockInputQueue::DoGetResampledData));
     ON_CALL(*this, PrepareToDelete(_)).WillByDefault(
         testing::Invoke(this, &MockInputQueue::DoPrepareToDelete));
   }
   ~MockInputQueue() override {}
 
   bool paused() const { return paused_; }
 
   // StreamMixerAlsa::InputQueue implementation:
   int input_samples_per_second() const override { return samples_per_second_; }
-  float volume_multiplier() const override { return multiplier_; }
   bool primary() const override { return primary_; }
   bool IsDeleting() const override { return deleting_; }
   MOCK_METHOD1(Initialize,
                void(const MediaPipelineBackendAlsa::RenderingDelay&
                         mixer_rendering_delay));
   int MaxReadSize() override { return max_read_size_; }
   MOCK_METHOD2(GetResampledData, void(::media::AudioBus* dest, int frames));
   MOCK_METHOD1(AfterWriteFrames,
                void(const MediaPipelineBackendAlsa::RenderingDelay&
                         mixer_rendering_delay));
@@ skipping 532 matching lines @@
   EXPECT_CALL(*inputs[0], AfterWriteFrames(_));
   EXPECT_CALL(*inputs[1], GetResampledData(_, _)).Times(0);
   EXPECT_CALL(*inputs[1], AfterWriteFrames(_));
 
   EXPECT_CALL(*mock_alsa(), PcmWritei(_, _, kNumFrames)).Times(1);
   mixer->WriteFramesForTest();
 }
 
 }  // namespace media
 }  // namespace chromecast