Eliminate media::Buffer as a base class for media::DecoderBuffer and media::DataBuffer.

It was never a good idea in the first place.

Our usage is exclusively with DecoderBuffers or DataBuffers. There's never a case where we benefit from using Buffer as a base class aside from hiding GetWriteableData(), however it's not a compelling enough reason to keep Buffer around.

BUG=169614
TBR=dmichael

Review URL: https://codereview.chromium.org/11880008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@176956 0039d316-1c4b-4281-b951-d872f2087c98

18 files changed, 225 insertions, 256 deletions

diff --git a/media/base/audio_decoder.h b/media/base/audio_decoder.h
index e6f09ed..ca43ecc 100644
--- a/media/base/audio_decoder.h
+++ b/media/base/audio_decoder.h
@@ -13,7 +13,7 @@
 
 namespace media {
 
-class Buffer;
+class DataBuffer;
 class DemuxerStream;
 
 class MEDIA_EXPORT AudioDecoder
@@ -43,7 +43,7 @@ class MEDIA_EXPORT AudioDecoder
   // indicate the end of the stream. A NULL buffer pointer indicates an aborted
   // Read(). This can happen if the DemuxerStream gets flushed and doesn't have
   // any more data to return.
-  typedef base::Callback<void(Status, const scoped_refptr<Buffer>&)> ReadCB;
+  typedef base::Callback<void(Status, const scoped_refptr<DataBuffer>&)> ReadCB;
   virtual void Read(const ReadCB& read_cb) = 0;
 
   // Reset decoder state, dropping any queued encoded data.
diff --git a/media/base/audio_splicer.cc b/media/base/audio_splicer.cc
index 2efbba9..e78cd2b 100644
--- a/media/base/audio_splicer.cc
+++ b/media/base/audio_splicer.cc
@@ -35,7 +35,7 @@ void AudioSplicer::Reset() {
   received_end_of_stream_ = false;
 }
 
-bool AudioSplicer::AddInput(const scoped_refptr<Buffer>& input){
+bool AudioSplicer::AddInput(const scoped_refptr<DataBuffer>& input){
   DCHECK(!received_end_of_stream_ || input->IsEndOfStream());
 
   if (input->IsEndOfStream()) {
@@ -125,13 +125,13 @@ bool AudioSplicer::HasNextBuffer() const {
   return !output_buffers_.empty();
 }
 
-scoped_refptr<Buffer> AudioSplicer::GetNextBuffer() {
-  scoped_refptr<Buffer> ret = output_buffers_.front();
+scoped_refptr<DataBuffer> AudioSplicer::GetNextBuffer() {
+  scoped_refptr<DataBuffer> ret = output_buffers_.front();
   output_buffers_.pop_front();
   return ret;
 }
 
-void AudioSplicer::AddOutputBuffer(const scoped_refptr<Buffer>& buffer) {
+void AudioSplicer::AddOutputBuffer(const scoped_refptr<DataBuffer>& buffer) {
   output_timestamp_helper_.AddBytes(buffer->GetDataSize());
   output_buffers_.push_back(buffer);
 }
diff --git a/media/base/audio_splicer.h b/media/base/audio_splicer.h
index aa97fae..22cce47 100644
--- a/media/base/audio_splicer.h
+++ b/media/base/audio_splicer.h
@@ -14,7 +14,7 @@
 namespace media {
 
 class AudioDecoderConfig;
-class Buffer;
+class DataBuffer;
 
 // Helper class that handles filling gaps and resolving overlaps.
 class MEDIA_EXPORT AudioSplicer {
@@ -29,17 +29,17 @@ class MEDIA_EXPORT AudioSplicer {
   // Adds a new buffer full of samples or end of stream buffer to the splicer.
   // Returns true if the buffer was accepted. False is returned if an error
   // occurred.
-  bool AddInput(const scoped_refptr<Buffer>& input);
+  bool AddInput(const scoped_refptr<DataBuffer>& input);
 
   // Returns true if the splicer has a buffer to return.
   bool HasNextBuffer() const;
 
   // Removes the next buffer from the output buffer queue and returns it.
   // This should only be called if HasNextBuffer() returns true.
-  scoped_refptr<Buffer> GetNextBuffer();
+  scoped_refptr<DataBuffer> GetNextBuffer();
 
  private:
-  void AddOutputBuffer(const scoped_refptr<Buffer>& buffer);
+  void AddOutputBuffer(const scoped_refptr<DataBuffer>& buffer);
 
   AudioTimestampHelper output_timestamp_helper_;
 
@@ -49,7 +49,7 @@ class MEDIA_EXPORT AudioSplicer {
   // in the source content.
   int min_gap_size_;
 
-  std::deque<scoped_refptr<Buffer> > output_buffers_;
+  std::deque<scoped_refptr<DataBuffer> > output_buffers_;
   bool received_end_of_stream_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(AudioSplicer);
diff --git a/media/base/audio_splicer_unittest.cc b/media/base/audio_splicer_unittest.cc
index 2096789..20c923f 100644
--- a/media/base/audio_splicer_unittest.cc
+++ b/media/base/audio_splicer_unittest.cc
@@ -23,11 +23,11 @@ class AudioSplicerTest : public ::testing::Test {
     input_timestamp_helper_.SetBaseTimestamp(base::TimeDelta());
   }
 
-  scoped_refptr<Buffer> GetNextInputBuffer(uint8 value) {
+  scoped_refptr<DataBuffer> GetNextInputBuffer(uint8 value) {
     return GetNextInputBuffer(value, kDefaultBufferSize);
   }
 
-  scoped_refptr<Buffer> GetNextInputBuffer(uint8 value, int size) {
+  scoped_refptr<DataBuffer> GetNextInputBuffer(uint8 value, int size) {
     scoped_refptr<DataBuffer> buffer = new DataBuffer(size);
     buffer->SetDataSize(size);
     memset(buffer->GetWritableData(), value, buffer->GetDataSize());
@@ -57,30 +57,30 @@ TEST_F(AudioSplicerTest, PassThru) {
   EXPECT_FALSE(splicer_.HasNextBuffer());
 
   // Test single buffer pass-thru behavior.
-  scoped_refptr<Buffer> input_1 = GetNextInputBuffer(1);
+  scoped_refptr<DataBuffer> input_1 = GetNextInputBuffer(1);
   EXPECT_TRUE(splicer_.AddInput(input_1));
   EXPECT_TRUE(splicer_.HasNextBuffer());
 
-  scoped_refptr<Buffer> output_1 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_1 = splicer_.GetNextBuffer();
   EXPECT_FALSE(splicer_.HasNextBuffer());
   EXPECT_EQ(input_1->GetTimestamp(), output_1->GetTimestamp());
   EXPECT_EQ(input_1->GetDuration(), output_1->GetDuration());
   EXPECT_EQ(input_1->GetDataSize(), output_1->GetDataSize());
 
   // Test that multiple buffers can be queued in the splicer.
-  scoped_refptr<Buffer> input_2 = GetNextInputBuffer(2);
-  scoped_refptr<Buffer> input_3 = GetNextInputBuffer(3);
+  scoped_refptr<DataBuffer> input_2 = GetNextInputBuffer(2);
+  scoped_refptr<DataBuffer> input_3 = GetNextInputBuffer(3);
   EXPECT_TRUE(splicer_.AddInput(input_2));
   EXPECT_TRUE(splicer_.AddInput(input_3));
   EXPECT_TRUE(splicer_.HasNextBuffer());
 
-  scoped_refptr<Buffer> output_2 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_2 = splicer_.GetNextBuffer();
   EXPECT_TRUE(splicer_.HasNextBuffer());
   EXPECT_EQ(input_2->GetTimestamp(), output_2->GetTimestamp());
   EXPECT_EQ(input_2->GetDuration(), output_2->GetDuration());
   EXPECT_EQ(input_2->GetDataSize(), output_2->GetDataSize());
 
-  scoped_refptr<Buffer> output_3 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_3 = splicer_.GetNextBuffer();
   EXPECT_FALSE(splicer_.HasNextBuffer());
   EXPECT_EQ(input_3->GetTimestamp(), output_3->GetTimestamp());
   EXPECT_EQ(input_3->GetDuration(), output_3->GetDuration());
@@ -88,7 +88,7 @@ TEST_F(AudioSplicerTest, PassThru) {
 }
 
 TEST_F(AudioSplicerTest, Reset) {
-  scoped_refptr<Buffer> input_1 = GetNextInputBuffer(1);
+  scoped_refptr<DataBuffer> input_1 = GetNextInputBuffer(1);
   EXPECT_TRUE(splicer_.AddInput(input_1));
   EXPECT_TRUE(splicer_.HasNextBuffer());
 
@@ -102,11 +102,11 @@ TEST_F(AudioSplicerTest, Reset) {
   input_timestamp_helper_.AddBytes(100 * kBytesPerFrame);
 
   // Verify that a new input buffer passes through as expected.
-  scoped_refptr<Buffer> input_2 = GetNextInputBuffer(2);
+  scoped_refptr<DataBuffer> input_2 = GetNextInputBuffer(2);
   EXPECT_TRUE(splicer_.AddInput(input_2));
   EXPECT_TRUE(splicer_.HasNextBuffer());
 
-  scoped_refptr<Buffer> output_2 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_2 = splicer_.GetNextBuffer();
   EXPECT_FALSE(splicer_.HasNextBuffer());
   EXPECT_EQ(input_2->GetTimestamp(), output_2->GetTimestamp());
   EXPECT_EQ(input_2->GetDuration(), output_2->GetDuration());
@@ -114,17 +114,17 @@ TEST_F(AudioSplicerTest, Reset) {
 }
 
 TEST_F(AudioSplicerTest, EndOfStream) {
-  scoped_refptr<Buffer> input_1 = GetNextInputBuffer(1);
-  scoped_refptr<Buffer> input_2 = new DataBuffer(0);  // End of stream.
-  scoped_refptr<Buffer> input_3 = GetNextInputBuffer(2);
+  scoped_refptr<DataBuffer> input_1 = GetNextInputBuffer(1);
+  scoped_refptr<DataBuffer> input_2 = new DataBuffer(0);  // End of stream.
+  scoped_refptr<DataBuffer> input_3 = GetNextInputBuffer(2);
   EXPECT_TRUE(input_2->IsEndOfStream());
 
   EXPECT_TRUE(splicer_.AddInput(input_1));
   EXPECT_TRUE(splicer_.AddInput(input_2));
   EXPECT_TRUE(splicer_.HasNextBuffer());
 
-  scoped_refptr<Buffer> output_1 = splicer_.GetNextBuffer();
-  scoped_refptr<Buffer> output_2 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_1 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_2 = splicer_.GetNextBuffer();
   EXPECT_FALSE(splicer_.HasNextBuffer());
   EXPECT_EQ(input_1->GetTimestamp(), output_1->GetTimestamp());
   EXPECT_EQ(input_1->GetDuration(), output_1->GetDuration());
@@ -135,7 +135,7 @@ TEST_F(AudioSplicerTest, EndOfStream) {
   // Verify that buffers can be added again after Reset().
   splicer_.Reset();
   EXPECT_TRUE(splicer_.AddInput(input_3));
-  scoped_refptr<Buffer> output_3 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_3 = splicer_.GetNextBuffer();
   EXPECT_FALSE(splicer_.HasNextBuffer());
   EXPECT_EQ(input_3->GetTimestamp(), output_3->GetTimestamp());
   EXPECT_EQ(input_3->GetDuration(), output_3->GetDuration());
@@ -152,23 +152,23 @@ TEST_F(AudioSplicerTest, EndOfStream) {
 // |11111111111111|0000|22222222222222|
 // +--------------+----+--------------+
 TEST_F(AudioSplicerTest, GapInsertion) {
-  scoped_refptr<Buffer> input_1 = GetNextInputBuffer(1);
+  scoped_refptr<DataBuffer> input_1 = GetNextInputBuffer(1);
 
   // Add bytes to the timestamp helper so that the next buffer
   // will have a starting timestamp that indicates a gap is
   // present.
   const int kGapSize = 7 * kBytesPerFrame;
   input_timestamp_helper_.AddBytes(kGapSize);
-  scoped_refptr<Buffer> input_2 = GetNextInputBuffer(2);
+  scoped_refptr<DataBuffer> input_2 = GetNextInputBuffer(2);
 
   EXPECT_TRUE(splicer_.AddInput(input_1));
   EXPECT_TRUE(splicer_.AddInput(input_2));
 
   // Verify that a gap buffer is generated.
   EXPECT_TRUE(splicer_.HasNextBuffer());
-  scoped_refptr<Buffer> output_1 = splicer_.GetNextBuffer();
-  scoped_refptr<Buffer> output_2 = splicer_.GetNextBuffer();
-  scoped_refptr<Buffer> output_3 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_1 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_2 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_3 = splicer_.GetNextBuffer();
   EXPECT_FALSE(splicer_.HasNextBuffer());
 
   // Verify that the first input buffer passed through unmodified.
@@ -198,19 +198,19 @@ TEST_F(AudioSplicerTest, GapInsertion) {
 // Test that an error is signalled when the gap between input buffers is
 // too large.
 TEST_F(AudioSplicerTest, GapTooLarge) {
-  scoped_refptr<Buffer> input_1 = GetNextInputBuffer(1);
+  scoped_refptr<DataBuffer> input_1 = GetNextInputBuffer(1);
 
   // Add a seconds worth of bytes so that an unacceptably large
   // gap exists between |input_1| and |input_2|.
   const int kGapSize = kDefaultSampleRate * kBytesPerFrame;
   input_timestamp_helper_.AddBytes(kGapSize);
-  scoped_refptr<Buffer> input_2 = GetNextInputBuffer(2);
+  scoped_refptr<DataBuffer> input_2 = GetNextInputBuffer(2);
 
   EXPECT_TRUE(splicer_.AddInput(input_1));
   EXPECT_FALSE(splicer_.AddInput(input_2));
 
   EXPECT_TRUE(splicer_.HasNextBuffer());
-  scoped_refptr<Buffer> output_1 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_1 = splicer_.GetNextBuffer();
 
   // Verify that the first input buffer passed through unmodified.
   EXPECT_EQ(input_1->GetTimestamp(), output_1->GetTimestamp());
@@ -227,10 +227,10 @@ TEST_F(AudioSplicerTest, GapTooLarge) {
       input_1->GetTimestamp() + input_1->GetDuration());
 
   // Verify that valid buffers are still accepted.
-  scoped_refptr<Buffer> input_3 = GetNextInputBuffer(3);
+  scoped_refptr<DataBuffer> input_3 = GetNextInputBuffer(3);
   EXPECT_TRUE(splicer_.AddInput(input_3));
   EXPECT_TRUE(splicer_.HasNextBuffer());
-  scoped_refptr<Buffer> output_2 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_2 = splicer_.GetNextBuffer();
   EXPECT_FALSE(splicer_.HasNextBuffer());
   EXPECT_EQ(input_3->GetTimestamp(), output_2->GetTimestamp());
   EXPECT_EQ(input_3->GetDuration(), output_2->GetDuration());
@@ -244,12 +244,12 @@ TEST_F(AudioSplicerTest, GapTooLarge) {
 TEST_F(AudioSplicerTest, BufferAddedBeforeBase) {
   input_timestamp_helper_.SetBaseTimestamp(
       base::TimeDelta::FromMicroseconds(10));
-  scoped_refptr<Buffer> input_1 = GetNextInputBuffer(1);
+  scoped_refptr<DataBuffer> input_1 = GetNextInputBuffer(1);
 
   // Reset the timestamp helper so the next buffer will have a timestamp earlier
   // than |input_1|.
   input_timestamp_helper_.SetBaseTimestamp(base::TimeDelta::FromSeconds(0));
-  scoped_refptr<Buffer> input_2 = GetNextInputBuffer(1);
+  scoped_refptr<DataBuffer> input_2 = GetNextInputBuffer(1);
 
   EXPECT_GT(input_1->GetTimestamp(), input_2->GetTimestamp());
   EXPECT_TRUE(splicer_.AddInput(input_1));
@@ -269,7 +269,7 @@ TEST_F(AudioSplicerTest, BufferAddedBeforeBase) {
 // |11111111111111|2222222222|
 // +--------------+----------+
 TEST_F(AudioSplicerTest, PartialOverlap) {
-  scoped_refptr<Buffer> input_1 = GetNextInputBuffer(1);
+  scoped_refptr<DataBuffer> input_1 = GetNextInputBuffer(1);
 
   // Reset timestamp helper so that the next buffer will have a
   // timestamp that starts in the middle of |input_1|.
@@ -277,14 +277,14 @@ TEST_F(AudioSplicerTest, PartialOverlap) {
   input_timestamp_helper_.SetBaseTimestamp(input_1->GetTimestamp());
   input_timestamp_helper_.AddBytes(input_1->GetDataSize() - kOverlapSize);
 
-  scoped_refptr<Buffer> input_2 = GetNextInputBuffer(2);
+  scoped_refptr<DataBuffer> input_2 = GetNextInputBuffer(2);
 
   EXPECT_TRUE(splicer_.AddInput(input_1));
   EXPECT_TRUE(splicer_.AddInput(input_2));
 
   EXPECT_TRUE(splicer_.HasNextBuffer());
-  scoped_refptr<Buffer> output_1 = splicer_.GetNextBuffer();
-  scoped_refptr<Buffer> output_2 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_1 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_2 = splicer_.GetNextBuffer();
   EXPECT_FALSE(splicer_.HasNextBuffer());
 
   // Verify that the first input buffer passed through unmodified.
@@ -323,7 +323,7 @@ TEST_F(AudioSplicerTest, PartialOverlap) {
 // |11111111111111|3333333333333|
 // +--------------+-------------+
 TEST_F(AudioSplicerTest, DropBuffer) {
-  scoped_refptr<Buffer> input_1 = GetNextInputBuffer(1);
+  scoped_refptr<DataBuffer> input_1 = GetNextInputBuffer(1);
 
   // Reset timestamp helper so that the next buffer will have a
   // timestamp that starts in the middle of |input_1|.
@@ -332,21 +332,21 @@ TEST_F(AudioSplicerTest, DropBuffer) {
   input_timestamp_helper_.SetBaseTimestamp(input_1->GetTimestamp());
   input_timestamp_helper_.AddBytes(kOverlapOffset);
 
-  scoped_refptr<Buffer> input_2 = GetNextInputBuffer(2, kOverlapSize);
+  scoped_refptr<DataBuffer> input_2 = GetNextInputBuffer(2, kOverlapSize);
 
   // Reset the timestamp helper so the next buffer will be right after
   // |input_1|.
   input_timestamp_helper_.SetBaseTimestamp(input_1->GetTimestamp());
   input_timestamp_helper_.AddBytes(input_1->GetDataSize());
-  scoped_refptr<Buffer> input_3 = GetNextInputBuffer(3);
+  scoped_refptr<DataBuffer> input_3 = GetNextInputBuffer(3);
 
   EXPECT_TRUE(splicer_.AddInput(input_1));
   EXPECT_TRUE(splicer_.AddInput(input_2));
   EXPECT_TRUE(splicer_.AddInput(input_3));
 
   EXPECT_TRUE(splicer_.HasNextBuffer());
-  scoped_refptr<Buffer> output_1 = splicer_.GetNextBuffer();
-  scoped_refptr<Buffer> output_2 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_1 = splicer_.GetNextBuffer();
+  scoped_refptr<DataBuffer> output_2 = splicer_.GetNextBuffer();
   EXPECT_FALSE(splicer_.HasNextBuffer());
 
   // Verify that the first input buffer passed through unmodified.
diff --git a/media/base/buffers.cc b/media/base/buffers.cc
deleted file mode 100644
index 63802c6..0000000
--- a/media/base/buffers.cc
+++ /dev/null
@@ -1,20 +0,0 @@
-// 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 "media/base/buffers.h"
-
-namespace media {
-
-Buffer::Buffer(base::TimeDelta timestamp, base::TimeDelta duration)
-    : timestamp_(timestamp),
-      duration_(duration) {
-}
-
-Buffer::~Buffer() {}
-
-bool Buffer::IsEndOfStream() const {
-  return GetData() == NULL;
-}
-
-}  // namespace media
diff --git a/media/base/buffers.h b/media/base/buffers.h
index d14f4db..7eecd5b 100644
--- a/media/base/buffers.h
+++ b/media/base/buffers.h
@@ -2,11 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Defines a base class for representing timestamped media data. Every buffer
-// contains a timestamp in microseconds describing the relative position of
-// the buffer within the media stream, and the duration in microseconds for
-// the length of time the buffer will be rendered.
-//
 // Timestamps are derived directly from the encoded media file and are commonly
 // known as the presentation timestamp (PTS).  Durations are a best-guess and
 // are usually derived from the sample/frame rate of the media file.
@@ -33,6 +28,8 @@
 
 namespace media {
 
+// TODO(scherkus): Move the contents of this file elsewhere.
+
 // Indicates an invalid or missing timestamp.
 MEDIA_EXPORT extern inline base::TimeDelta kNoTimestamp() {
   return base::TimeDelta::FromMicroseconds(kint64min);
@@ -43,43 +40,6 @@ MEDIA_EXPORT extern inline base::TimeDelta kInfiniteDuration() {
   return base::TimeDelta::FromMicroseconds(kint64max);
 }
 
-class MEDIA_EXPORT Buffer : public base::RefCountedThreadSafe<Buffer> {
- public:
-  // Returns a read only pointer to the buffer data.
-  virtual const uint8* GetData() const = 0;
-
-  // Returns the size of valid data in bytes.
-  virtual int GetDataSize() const = 0;
-
-  // If there's no data in this buffer, it represents end of stream.
-  bool IsEndOfStream() const;
-
-  base::TimeDelta GetTimestamp() const {
-    return timestamp_;
-  }
-  void SetTimestamp(const base::TimeDelta& timestamp) {
-    timestamp_ = timestamp;
-  }
-
-  base::TimeDelta GetDuration() const {
-    return duration_;
-  }
-  void SetDuration(const base::TimeDelta& duration) {
-    duration_ = duration;
-  }
-
- protected:
-  friend class base::RefCountedThreadSafe<Buffer>;
-  Buffer(base::TimeDelta timestamp, base::TimeDelta duration);
-  virtual ~Buffer();
-
- private:
-  base::TimeDelta timestamp_;
-  base::TimeDelta duration_;
-
-  DISALLOW_COPY_AND_ASSIGN(Buffer);
-};
-
 }  // namespace media
 
 #endif  // MEDIA_BASE_BUFFERS_H_
diff --git a/media/base/buffers_unittest.cc b/media/base/buffers_unittest.cc
deleted file mode 100644
index a96b40b..0000000
--- a/media/base/buffers_unittest.cc
+++ /dev/null
@@ -1,85 +0,0 @@
-// 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/string_util.h"
-#include "media/base/buffers.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace media {
-
-namespace {
-
-// Simple implementation of Buffer to test base class functionality.
-class TestBuffer : public Buffer {
- public:
-  TestBuffer()
-      : Buffer(base::TimeDelta(), base::TimeDelta()) {
-  }
-
-  // Sets |data_| and |size_| members for testing purposes. Does not take
-  // ownership of |data|.
-  TestBuffer(const uint8* data, int size)
-      : Buffer(base::TimeDelta(), base::TimeDelta()),
-        data_(data),
-        size_(size) {
-  }
-
-  // Buffer implementation.
-  virtual const uint8* GetData() const OVERRIDE { return data_; }
-  virtual int GetDataSize() const OVERRIDE { return size_; }
-
- protected:
-  virtual ~TestBuffer() {}
-
- private:
-  const uint8* data_;
-  int size_;
-
-  DISALLOW_COPY_AND_ASSIGN(TestBuffer);
-};
-
-}  // namespace
-
-TEST(BufferTest, Timestamp) {
-  const base::TimeDelta kZero;
-  const base::TimeDelta kTimestampA = base::TimeDelta::FromMicroseconds(1337);
-  const base::TimeDelta kTimestampB = base::TimeDelta::FromMicroseconds(1234);
-
-  scoped_refptr<TestBuffer> buffer = new TestBuffer();
-  EXPECT_TRUE(buffer->GetTimestamp() == kZero);
-
-  buffer->SetTimestamp(kTimestampA);
-  EXPECT_TRUE(buffer->GetTimestamp() == kTimestampA);
-
-  buffer->SetTimestamp(kTimestampB);
-  EXPECT_TRUE(buffer->GetTimestamp() == kTimestampB);
-}
-
-TEST(BufferTest, Duration) {
-  const base::TimeDelta kZero;
-  const base::TimeDelta kDurationA = base::TimeDelta::FromMicroseconds(1337);
-  const base::TimeDelta kDurationB = base::TimeDelta::FromMicroseconds(1234);
-
-  scoped_refptr<TestBuffer> buffer = new TestBuffer();
-  EXPECT_TRUE(buffer->GetDuration() == kZero);
-
-  buffer->SetDuration(kDurationA);
-  EXPECT_TRUE(buffer->GetDuration() == kDurationA);
-
-  buffer->SetDuration(kDurationB);
-  EXPECT_TRUE(buffer->GetDuration() == kDurationB);
-}
-
-TEST(BufferTest, IsEndOfStream) {
-  const uint8 kData[] = { 0x00, 0xFF };
-  const int kDataSize = arraysize(kData);
-
-  scoped_refptr<TestBuffer> buffer = new TestBuffer(NULL, 0);
-  EXPECT_TRUE(buffer->IsEndOfStream());
-
-  buffer = new TestBuffer(kData, kDataSize);
-  EXPECT_FALSE(buffer->IsEndOfStream());
-}
-
-}  // namespace media
diff --git a/media/base/data_buffer.cc b/media/base/data_buffer.cc
index 28ca491..a342023 100644
--- a/media/base/data_buffer.cc
+++ b/media/base/data_buffer.cc
@@ -9,22 +9,19 @@
 namespace media {
 
 DataBuffer::DataBuffer(scoped_array<uint8> buffer, int buffer_size)
-    : Buffer(base::TimeDelta(), base::TimeDelta()),
-      data_(buffer.Pass()),
+    : data_(buffer.Pass()),
       buffer_size_(buffer_size),
       data_size_(buffer_size) {
 }
 
 DataBuffer::DataBuffer(int buffer_size)
-    : Buffer(base::TimeDelta(), base::TimeDelta()),
-      buffer_size_(buffer_size),
+    : buffer_size_(buffer_size),
       data_size_(0) {
   Initialize();
 }
 
 DataBuffer::DataBuffer(const uint8* data, int data_size)
-    : Buffer(base::TimeDelta(), base::TimeDelta()),
-      buffer_size_(data_size),
+    : buffer_size_(data_size),
       data_size_(data_size) {
   Initialize();
   memcpy(data_.get(), data, data_size_);
@@ -43,18 +40,38 @@ void DataBuffer::Initialize() {
   data_.reset(new uint8[buffer_size_]);
 }
 
-const uint8* DataBuffer::GetData() const {
-  return data_.get();
+base::TimeDelta DataBuffer::GetTimestamp() const {
+  return timestamp_;
 }
 
-int DataBuffer::GetDataSize() const {
-  return data_size_;
+void DataBuffer::SetTimestamp(const base::TimeDelta& timestamp) {
+  timestamp_ = timestamp;
+}
+
+base::TimeDelta DataBuffer::GetDuration() const {
+  return duration_;
+}
+
+void DataBuffer::SetDuration(const base::TimeDelta& duration) {
+  duration_ = duration;
+}
+
+bool DataBuffer::IsEndOfStream() const {
+  return data_ == NULL;
+}
+
+const uint8* DataBuffer::GetData() const {
+  return data_.get();
 }
 
 uint8* DataBuffer::GetWritableData() {
   return data_.get();
 }
 
+int DataBuffer::GetDataSize() const {
+  return data_size_;
+}
+
 void DataBuffer::SetDataSize(int data_size) {
   DCHECK_LE(data_size, buffer_size_);
   data_size_ = data_size;
diff --git a/media/base/data_buffer.h b/media/base/data_buffer.h
index 96e9af5..d3ccd37 100644
--- a/media/base/data_buffer.h
+++ b/media/base/data_buffer.h
@@ -2,53 +2,68 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// A simple implementation of Buffer that takes ownership of the given data
-// pointer.
-//
-// DataBuffer assumes that memory was allocated with new uint8[].
-
 #ifndef MEDIA_BASE_DATA_BUFFER_H_
 #define MEDIA_BASE_DATA_BUFFER_H_
 
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "media/base/buffers.h"
+#include "base/time.h"
+#include "media/base/media_export.h"
 
 namespace media {
 
-class MEDIA_EXPORT DataBuffer : public Buffer {
+// A simple buffer that takes ownership of the given data pointer or allocates
+// as necessary.
+//
+// Unlike DecoderBuffer, allocations are assumed to be allocated with the
+// default memory allocator (i.e., new uint8[]).
+class MEDIA_EXPORT DataBuffer : public base::RefCountedThreadSafe<DataBuffer> {
  public:
   // Assumes valid data of size |buffer_size|.
   DataBuffer(scoped_array<uint8> buffer, int buffer_size);
 
   // Allocates buffer of size |buffer_size|. If |buffer_size| is 0, |data_| is
-  // set to a NULL ptr.
+  // set to NULL and this becomes an end of stream buffer.
+  //
+  // TODO(scherkus): Enforce calling CreateEOSBuffer() instead of passing 0 and
+  // sprinkle DCHECK()s everywhere.
   explicit DataBuffer(int buffer_size);
 
   // Allocates buffer of size |data_size|, copies [data,data+data_size) to
   // the allocated buffer and sets data size to |data_size|.
   DataBuffer(const uint8* data, int data_size);
 
-  // Buffer implementation.
-  virtual const uint8* GetData() const OVERRIDE;
-  virtual int GetDataSize() const OVERRIDE;
+  base::TimeDelta GetTimestamp() const;
+  void SetTimestamp(const base::TimeDelta& timestamp);
 
-  // Returns a read-write pointer to the buffer data.
-  virtual uint8* GetWritableData();
+  base::TimeDelta GetDuration() const;
+  void SetDuration(const base::TimeDelta& duration);
 
-  // Updates the size of valid data in bytes, which must be less than or equal
+  const uint8* GetData() const;
+  uint8* GetWritableData();
+
+  // The size of valid data in bytes, which must be less than or equal
   // to GetBufferSize().
-  virtual void SetDataSize(int data_size);
+  int GetDataSize() const;
+  void SetDataSize(int data_size);
 
   // Returns the size of the underlying buffer.
-  virtual int GetBufferSize() const;
+  int GetBufferSize() const;
+
+  // If there's no data in this buffer, it represents end of stream.
+  bool IsEndOfStream() const;
 
  protected:
+  friend class base::RefCountedThreadSafe<DataBuffer>;
   virtual ~DataBuffer();
 
  private:
   // Constructor helper method for memory allocations.
   void Initialize();
 
+  base::TimeDelta timestamp_;
+  base::TimeDelta duration_;
+
   scoped_array<uint8> data_;
   int buffer_size_;
   int data_size_;
diff --git a/media/base/data_buffer_unittest.cc b/media/base/data_buffer_unittest.cc
index 71d8389..0daa5f6 100644
--- a/media/base/data_buffer_unittest.cc
+++ b/media/base/data_buffer_unittest.cc
@@ -28,6 +28,47 @@ TEST(DataBufferTest, Constructors) {
   ASSERT_NE(0, memcmp(buffer3->GetData(), kTestData, kTestDataSize));
 }
 
+TEST(DataBufferTest, Timestamp) {
+  const base::TimeDelta kZero;
+  const base::TimeDelta kTimestampA = base::TimeDelta::FromMicroseconds(1337);
+  const base::TimeDelta kTimestampB = base::TimeDelta::FromMicroseconds(1234);
+
+  scoped_refptr<DataBuffer> buffer = new DataBuffer(0);
+  EXPECT_TRUE(buffer->GetTimestamp() == kZero);
+
+  buffer->SetTimestamp(kTimestampA);
+  EXPECT_TRUE(buffer->GetTimestamp() == kTimestampA);
+
+  buffer->SetTimestamp(kTimestampB);
+  EXPECT_TRUE(buffer->GetTimestamp() == kTimestampB);
+}
+
+TEST(DataBufferTest, Duration) {
+  const base::TimeDelta kZero;
+  const base::TimeDelta kDurationA = base::TimeDelta::FromMicroseconds(1337);
+  const base::TimeDelta kDurationB = base::TimeDelta::FromMicroseconds(1234);
+
+  scoped_refptr<DataBuffer> buffer = new DataBuffer(0);
+  EXPECT_TRUE(buffer->GetDuration() == kZero);
+
+  buffer->SetDuration(kDurationA);
+  EXPECT_TRUE(buffer->GetDuration() == kDurationA);
+
+  buffer->SetDuration(kDurationB);
+  EXPECT_TRUE(buffer->GetDuration() == kDurationB);
+}
+
+TEST(DataBufferTest, IsEndOfStream) {
+  const uint8 kData[] = { 0x00, 0xFF };
+  const int kDataSize = arraysize(kData);
+
+  scoped_refptr<DataBuffer> buffer = new DataBuffer(0);
+  EXPECT_TRUE(buffer->IsEndOfStream());
+
+  buffer = new DataBuffer(kData, kDataSize);
+  EXPECT_FALSE(buffer->IsEndOfStream());
+}
+
 TEST(DataBufferTest, ReadingWriting) {
   const char kData[] = "hello";
   const int kDataSize = arraysize(kData);
diff --git a/media/base/decoder_buffer.cc b/media/base/decoder_buffer.cc
index e4af00e..9cc54ae 100644
--- a/media/base/decoder_buffer.cc
+++ b/media/base/decoder_buffer.cc
@@ -10,14 +10,12 @@
 namespace media {
 
 DecoderBuffer::DecoderBuffer(int buffer_size)
-    : Buffer(base::TimeDelta(), base::TimeDelta()),
-      buffer_size_(buffer_size) {
+    : buffer_size_(buffer_size) {
   Initialize();
 }
 
 DecoderBuffer::DecoderBuffer(const uint8* data, int buffer_size)
-    : Buffer(base::TimeDelta(), base::TimeDelta()),
-      buffer_size_(buffer_size) {
+    : buffer_size_(buffer_size) {
   // Prevent invalid allocations.  Also used to create end of stream buffers.
   if (!data || buffer_size <= 0) {
     buffer_size_ = 0;
@@ -47,16 +45,32 @@ scoped_refptr<DecoderBuffer> DecoderBuffer::CreateEOSBuffer() {
   return make_scoped_refptr(new DecoderBuffer(NULL, 0));
 }
 
+base::TimeDelta DecoderBuffer::GetTimestamp() const {
+  return timestamp_;
+}
+
+void DecoderBuffer::SetTimestamp(const base::TimeDelta& timestamp) {
+  timestamp_ = timestamp;
+}
+
+base::TimeDelta DecoderBuffer::GetDuration() const {
+  return duration_;
+}
+
+void DecoderBuffer::SetDuration(const base::TimeDelta& duration) {
+  duration_ = duration;
+}
+
 const uint8* DecoderBuffer::GetData() const {
   return data_.get();
 }
 
-int DecoderBuffer::GetDataSize() const {
-  return buffer_size_;
+uint8* DecoderBuffer::GetWritableData() const {
+  return data_.get();
 }
 
-uint8* DecoderBuffer::GetWritableData() {
-  return data_.get();
+int DecoderBuffer::GetDataSize() const {
+  return buffer_size_;
 }
 
 const DecryptConfig* DecoderBuffer::GetDecryptConfig() const {
@@ -67,4 +81,8 @@ void DecoderBuffer::SetDecryptConfig(scoped_ptr<DecryptConfig> decrypt_config) {
   decrypt_config_ = decrypt_config.Pass();
 }
 
+bool DecoderBuffer::IsEndOfStream() const {
+  return data_ == NULL;
+}
+
 }  // namespace media
diff --git a/media/base/decoder_buffer.h b/media/base/decoder_buffer.h
index 50b0855..dca8776 100644
--- a/media/base/decoder_buffer.h
+++ b/media/base/decoder_buffer.h
@@ -2,26 +2,29 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// A specialized buffer for interfacing with audio / video decoders.
-//
-// Specifically ensures that data is aligned and padded as necessary by the
-// underlying decoding framework.  On desktop platforms this means memory is
-// allocated using FFmpeg with particular alignment and padding requirements.
-//
-// Also includes decoder specific functionality for decryption.
-
 #ifndef MEDIA_BASE_DECODER_BUFFER_H_
 #define MEDIA_BASE_DECODER_BUFFER_H_
 
 #include "base/memory/aligned_memory.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/time.h"
 #include "build/build_config.h"
-#include "media/base/buffers.h"
-#include "media/base/decrypt_config.h"
+#include "media/base/media_export.h"
 
 namespace media {
 
-class MEDIA_EXPORT DecoderBuffer : public Buffer {
+class DecryptConfig;
+
+// A specialized buffer for interfacing with audio / video decoders.
+//
+// Specifically ensures that data is aligned and padded as necessary by the
+// underlying decoding framework.  On desktop platforms this means memory is
+// allocated using FFmpeg with particular alignment and padding requirements.
+//
+// Also includes decoder specific functionality for decryption.
+class MEDIA_EXPORT DecoderBuffer
+    : public base::RefCountedThreadSafe<DecoderBuffer> {
  public:
   enum {
     kPaddingSize = 16,
@@ -44,17 +47,29 @@ class MEDIA_EXPORT DecoderBuffer : public Buffer {
   // and GetWritableData() will return NULL and GetDataSize() will return 0.
   static scoped_refptr<DecoderBuffer> CreateEOSBuffer();
 
-  // Buffer implementation.
-  virtual const uint8* GetData() const OVERRIDE;
-  virtual int GetDataSize() const OVERRIDE;
+  base::TimeDelta GetTimestamp() const;
+  void SetTimestamp(const base::TimeDelta& timestamp);
 
-  // Returns a read-write pointer to the buffer data.
-  virtual uint8* GetWritableData();
+  base::TimeDelta GetDuration() const;
+  void SetDuration(const base::TimeDelta& duration);
 
-  virtual const DecryptConfig* GetDecryptConfig() const;
-  virtual void SetDecryptConfig(scoped_ptr<DecryptConfig> decrypt_config);
+  const uint8* GetData() const;
+  uint8* GetWritableData() const;
+
+  int GetDataSize() const;
+
+  const DecryptConfig* GetDecryptConfig() const;
+  void SetDecryptConfig(scoped_ptr<DecryptConfig> decrypt_config);
+
+  // If there's no data in this buffer, it represents end of stream.
+  //
+  // TODO(scherkus): Change to be an actual settable flag as opposed to being
+  // based on the value of |data_|, see http://crbug.com/169133
+  bool IsEndOfStream() const;
 
  protected:
+  friend class base::RefCountedThreadSafe<DecoderBuffer>;
+
   // Allocates a buffer of size |size| >= 0 and copies |data| into it.  Buffer
   // will be padded and aligned as necessary.  If |data| is NULL then |data_| is
   // set to NULL and |buffer_size_| to 0.
@@ -62,6 +77,9 @@ class MEDIA_EXPORT DecoderBuffer : public Buffer {
   virtual ~DecoderBuffer();
 
  private:
+  base::TimeDelta timestamp_;
+  base::TimeDelta duration_;
+
   int buffer_size_;
   scoped_ptr<uint8, base::ScopedPtrAlignedFree> data_;
   scoped_ptr<DecryptConfig> decrypt_config_;
diff --git a/media/base/decoder_buffer_queue.cc b/media/base/decoder_buffer_queue.cc
index ad91c37..ab24c2d 100644
--- a/media/base/decoder_buffer_queue.cc
+++ b/media/base/decoder_buffer_queue.cc
@@ -5,6 +5,7 @@
 #include "media/base/decoder_buffer_queue.h"
 
 #include "base/logging.h"
+#include "media/base/buffers.h"
 #include "media/base/decoder_buffer.h"
 
 namespace media {
diff --git a/media/base/decoder_buffer_queue_unittest.cc b/media/base/decoder_buffer_queue_unittest.cc
index 02cd541..243e465 100644
--- a/media/base/decoder_buffer_queue_unittest.cc
+++ b/media/base/decoder_buffer_queue_unittest.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "media/base/buffers.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/decoder_buffer_queue.h"
 #include "testing/gtest/include/gtest/gtest.h"
diff --git a/media/base/decryptor.h b/media/base/decryptor.h
index 4cc05a1..f27a7bf 100644
--- a/media/base/decryptor.h
+++ b/media/base/decryptor.h
@@ -17,7 +17,7 @@
 namespace media {
 
 class AudioDecoderConfig;
-class Buffer;
+class DataBuffer;
 class DecoderBuffer;
 class VideoDecoderConfig;
 class VideoFrame;
@@ -146,7 +146,7 @@ class MEDIA_EXPORT Decryptor {
 
   // Helper structure for managing multiple decoded audio buffers per input.
   // TODO(xhwang): Rename this to AudioFrames.
-  typedef std::list<scoped_refptr<Buffer> > AudioBuffers;
+  typedef std::list<scoped_refptr<DataBuffer> > AudioBuffers;
 
   // Indicates completion of audio/video decrypt-and-decode operation.
   //
diff --git a/media/base/seekable_buffer.cc b/media/base/seekable_buffer.cc
index 48c0858..b23457e 100644
--- a/media/base/seekable_buffer.cc
+++ b/media/base/seekable_buffer.cc
@@ -60,14 +60,14 @@ bool SeekableBuffer::GetCurrentChunk(const uint8** data, int* size) const {
   return true;
 }
 
-bool SeekableBuffer::Append(Buffer* buffer_in) {
+bool SeekableBuffer::Append(const scoped_refptr<DataBuffer>& buffer_in) {
   if (buffers_.empty() && buffer_in->GetTimestamp() != kNoTimestamp()) {
     current_time_ = buffer_in->GetTimestamp();
   }
 
   // Since the forward capacity is only used to check the criteria for buffer
   // full, we always append data to the buffer.
-  buffers_.push_back(scoped_refptr<Buffer>(buffer_in));
+  buffers_.push_back(buffer_in);
 
   // After we have written the first buffer, update |current_buffer_| to point
   // to it.
@@ -172,7 +172,7 @@ void SeekableBuffer::EvictBackwardBuffers() {
     BufferQueue::iterator i = buffers_.begin();
     if (i == current_buffer_)
       break;
-    scoped_refptr<Buffer> buffer = *i;
+    scoped_refptr<DataBuffer> buffer = *i;
     backward_bytes_ -= buffer->GetDataSize();
     DCHECK_GE(backward_bytes_, 0);
 
@@ -196,7 +196,7 @@ int SeekableBuffer::InternalRead(uint8* data, int size,
     if (current_buffer == buffers_.end())
       break;
 
-    scoped_refptr<Buffer> buffer = *current_buffer;
+    scoped_refptr<DataBuffer> buffer = *current_buffer;
 
     int remaining_bytes_in_buffer =
         buffer->GetDataSize() - current_buffer_offset;
diff --git a/media/base/seekable_buffer.h b/media/base/seekable_buffer.h
index 0a3ff72..41d26fe 100644
--- a/media/base/seekable_buffer.h
+++ b/media/base/seekable_buffer.h
@@ -41,6 +41,8 @@
 
 namespace media {
 
+class DataBuffer;
+
 class MEDIA_EXPORT SeekableBuffer {
  public:
   // Constructs an instance with |forward_capacity| and |backward_capacity|.
@@ -75,7 +77,7 @@ class MEDIA_EXPORT SeekableBuffer {
   // Appends |buffer_in| to this buffer. Returns false if forward_bytes() is
   // greater than or equals to forward_capacity(), true otherwise. The data
   // is added to the buffer in any case.
-  bool Append(Buffer* buffer_in);
+  bool Append(const scoped_refptr<DataBuffer>& buffer_in);
 
   // Appends |size| bytes of |data| to the buffer. Result is the same
   // as for Append(Buffer*).
@@ -128,7 +130,7 @@ class MEDIA_EXPORT SeekableBuffer {
 
  private:
   // Definition of the buffer queue.
-  typedef std::list<scoped_refptr<Buffer> > BufferQueue;
+  typedef std::list<scoped_refptr<DataBuffer> > BufferQueue;
 
   // A helper method to evict buffers in the backward direction until backward
   // bytes is within the backward capacity.
diff --git a/media/base/stream_parser_buffer.cc b/media/base/stream_parser_buffer.cc
index 04f9513..13e649e 100644
--- a/media/base/stream_parser_buffer.cc
+++ b/media/base/stream_parser_buffer.cc
@@ -5,6 +5,7 @@
 #include "media/base/stream_parser_buffer.h"
 
 #include "base/logging.h"
+#include "media/base/buffers.h"
 
 namespace media {