Add a silent audio sink to consume WebAudio data on silence detection.

media/base/audio_bus_unittest.cc

 // Copyright (c) 2012 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 "base/strings/stringprintf.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "media/audio/audio_parameters.h"
 #include "media/base/audio_bus.h"
 #include "media/base/channel_layout.h"
@@ skipping 187 matching lines @@
   }
 }
 
 // Verify Zero() and ZeroFrames(...) utility methods work as advertised.
 TEST_F(AudioBusTest, Zero) {
   scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, kFrameCount);
 
   // Fill the bus with dummy data.
   for (int i = 0; i < bus->channels(); ++i)
     std::fill(bus->channel(i), bus->channel(i) + bus->frames(), i + 1);
+  EXPECT_FALSE(bus->AreFramesZero());
 
   // Zero first half the frames of each channel.
   bus->ZeroFrames(kFrameCount / 2);
   for (int i = 0; i < bus->channels(); ++i) {
     SCOPED_TRACE("First Half Zero");
     VerifyValue(bus->channel(i), kFrameCount / 2, 0);
     VerifyValue(bus->channel(i) + kFrameCount / 2,
                 kFrameCount - kFrameCount / 2, i + 1);
   }
+  EXPECT_FALSE(bus->AreFramesZero());
 
   // Fill the bus with dummy data.
   for (int i = 0; i < bus->channels(); ++i)
     std::fill(bus->channel(i), bus->channel(i) + bus->frames(), i + 1);
 
   // Zero the last half of the frames.
   bus->ZeroFramesPartial(kFrameCount / 2, kFrameCount - kFrameCount / 2);
   for (int i = 0; i < bus->channels(); ++i) {
     SCOPED_TRACE("Last Half Zero");
     VerifyValue(bus->channel(i) + kFrameCount / 2,
                 kFrameCount - kFrameCount / 2, 0);
     VerifyValue(bus->channel(i), kFrameCount / 2, i + 1);
   }
+  EXPECT_FALSE(bus->AreFramesZero());
 
   // Fill the bus with dummy data.
   for (int i = 0; i < bus->channels(); ++i)
     std::fill(bus->channel(i), bus->channel(i) + bus->frames(), i + 1);
 
   // Zero all the frames of each channel.
   bus->Zero();
   for (int i = 0; i < bus->channels(); ++i) {
     SCOPED_TRACE("All Zero");
     VerifyValue(bus->channel(i), bus->frames(), 0);
   }
+  EXPECT_TRUE(bus->AreFramesZero());
 }
 
 // Each test vector represents two channels of data in the following arbitrary
 // layout: <min, zero, max, min, max / 2, min / 2, zero, max, zero, zero>.
 static const int kTestVectorSize = 10;
 static const uint8 kTestVectorUint8[kTestVectorSize] = {
     0, -kint8min, kuint8max, 0, kint8max / 2 + 128, kint8min / 2 + 128,
     -kint8min, kuint8max, -kint8min, -kint8min };
 static const int16 kTestVectorInt16[kTestVectorSize] = {
     kint16min, 0, kint16max, kint16min, kint16max / 2, kint16min / 2,
@@ skipping 156 matching lines @@
 
   // Verify zero volume case.
   bus->Scale(0);
   for (int i = 0; i < bus->channels(); ++i) {
     SCOPED_TRACE("Zero Scale");
     VerifyValue(bus->channel(i), bus->frames(), 0);
   }
 }
 
 }  // namespace media