Revert of Remove AudioBuffer::set_duration(), instead base on frames.

media/base/audio_discard_helper_unittest.cc

 // Copyright 2014 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/memory/scoped_ptr.h"
 #include "media/base/audio_buffer.h"
 #include "media/base/audio_bus.h"
 #include "media/base/audio_discard_helper.h"
 #include "media/base/buffers.h"
 #include "media/base/decoder_buffer.h"
@@ skipping 15 matching lines @@
 }
 
 static scoped_refptr<AudioBuffer> CreateDecodedBuffer(int frames) {
   return MakeAudioBuffer(kSampleFormatPlanarF32,
                          CHANNEL_LAYOUT_MONO,
                          1,
                          kSampleRate,
                          0.0f,
                          kDataStep,
                          frames,
+                         kNoTimestamp(),
                          kNoTimestamp());
 }
 
 static float ExtractDecodedData(const scoped_refptr<AudioBuffer>& buffer,
                                 int index) {
   // This is really inefficient, but we can't access the raw AudioBuffer if any
   // start trimming has been applied.
   scoped_ptr<AudioBus> temp_bus = AudioBus::Create(buffer->channel_count(), 1);
   buffer->ReadFrames(1, index, 0, temp_bus.get());
   return temp_bus->channel(0)[0];
@@ skipping 205 matching lines @@
   ASSERT_TRUE(discard_helper.ProcessBuffers(encoded_buffer, decoded_buffer));
   ASSERT_TRUE(discard_helper.initialized());
   EXPECT_EQ(kTimestamp, decoded_buffer->timestamp());
   EXPECT_EQ(kDuration / 2, decoded_buffer->duration());
   EXPECT_EQ(kTestFrames / 2, decoded_buffer->frame_count());
   ASSERT_FLOAT_EQ(kDiscardFrames * kDataStep,
                   ExtractDecodedData(decoded_buffer, 0));
 }
 
 }  // namespace media