Add vector_math::FMUL. Replace audio_util::AdjustVolume.

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 <limits>
 
 #include "base/stringprintf.h"
 #include "base/time.h"
 #include "media/audio/audio_parameters.h"
 #include "media/base/audio_bus.h"
@@ skipping 338 matching lines @@
   }
 
   int16 test_array[arraysize(kTestVectorInt16)];
   expected->ToInterleavedPartial(
       kPartialStart, kPartialFrames, sizeof(*kTestVectorInt16), test_array);
   ASSERT_EQ(memcmp(
       test_array, kTestVectorInt16 + kPartialStart * kTestVectorChannels,
       kPartialFrames * sizeof(*kTestVectorInt16) * kTestVectorChannels), 0);
 }
 
+TEST_F(AudioBusTest, Scale) {
+  scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, kFrameCount);
+
+  // Fill the bus with dummy data.
+  static const float kFillValue = 1;
+  for (int i = 0; i < bus->channels(); ++i)
+    std::fill(bus->channel(i), bus->channel(i) + bus->frames(), kFillValue);
+
+  // Adjust by an invalid volume and ensure volume is unchanged.
+  bus->Scale(-1);
+  for (int i = 0; i < bus->channels(); ++i) {
+    SCOPED_TRACE("Invalid Scale");
+    VerifyValue(bus->channel(i), bus->frames(), kFillValue);
+  }
+
+  // Verify correct volume adjustment.
+  static const float kVolume = 0.5;
+  bus->Scale(kVolume);
+  for (int i = 0; i < bus->channels(); ++i) {
+    SCOPED_TRACE("Half Scale");
+    VerifyValue(bus->channel(i), bus->frames(), kFillValue * kVolume);
+  }
+
+  // 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