Take advantage of the new Pass() machinery on scoped_ptr{,_malloc}.

Pass() was announced in 
https://groups.google.com/a/chromium.org/d/topic/chromium-dev/RTd7rNxHjqk/discussion
This CL replaces comments about ownership transfer (in all files whose paths
contain media/) with the explicit passing of the appropriate scoper.

The exceptions that are not touched by this CL:
- scoped_refptr<> doesn't support Pass() and so is untouched.
- media/audio code defines its own callback machinery, mimicking the old-style
  callbacks (pass by pointer, explicit deletes).  I think that whole pile needs
  to be replaced with new-style (Bind) callbacks, so left it alone for now.

BUG=none
TEST=trybots


Review URL: http://codereview.chromium.org/9015015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@117009 0039d316-1c4b-4281-b951-d872f2087c98

17 files changed, 120 insertions, 119 deletions

diff --git a/media/base/async_filter_factory_base.h b/media/base/async_filter_factory_base.h
index 303bad9..4a9200e 100644
--- a/media/base/async_filter_factory_base.h
+++ b/media/base/async_filter_factory_base.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -62,7 +62,7 @@ class MEDIA_EXPORT AsyncDataSourceFactoryBase : public DataSourceFactory {
   // NOTE: Nothing in this base class needs to be cloned because this class
   // only keeps track of pending requests, which are not part of the cloning
   // process.
-  virtual DataSourceFactory* Clone() const = 0;
+  virtual scoped_ptr<DataSourceFactory> Clone() const = 0;
 
  protected:
   class MEDIA_EXPORT BuildRequest {
diff --git a/media/base/composite_data_source_factory.cc b/media/base/composite_data_source_factory.cc
index e751505..c0c28e1 100644
--- a/media/base/composite_data_source_factory.cc
+++ b/media/base/composite_data_source_factory.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -26,7 +26,7 @@ class CompositeDataSourceFactory::BuildRequest
   void CallNextFactory();
   void OnBuildDone(PipelineStatus status, DataSource* data_source);
 
-  FactoryList factories_;
+  FactoryList factories_;  // Not owned by this class.
 };
 
 CompositeDataSourceFactory::CompositeDataSourceFactory() {}
@@ -35,21 +35,25 @@ CompositeDataSourceFactory::~CompositeDataSourceFactory() {
   STLDeleteElements(&factories_);
 }
 
-void CompositeDataSourceFactory::AddFactory(DataSourceFactory* factory) {
-  DCHECK(factory);
-  factories_.push_back(factory);
+void CompositeDataSourceFactory::AddFactory(
+    scoped_ptr<DataSourceFactory> factory) {
+  DCHECK(factory.get());
+  factories_.push_back(factory.release());
 }
 
-DataSourceFactory* CompositeDataSourceFactory::Clone() const {
-  CompositeDataSourceFactory* new_factory = new CompositeDataSourceFactory();
+scoped_ptr<DataSourceFactory> CompositeDataSourceFactory::Clone() const {
+  scoped_ptr<CompositeDataSourceFactory> new_factory(
+      new CompositeDataSourceFactory());
 
   for (FactoryList::const_iterator itr = factories_.begin();
        itr != factories_.end();
        ++itr) {
-    new_factory->AddFactory((*itr)->Clone());
+    new_factory->AddFactory((*itr)->Clone().Pass());
   }
 
-  return new_factory;
+  // TODO(fischman): replace the extra scoped_ptr+release() with Pass() when
+  // http://crbug.com/109026 is fixed.
+  return scoped_ptr<DataSourceFactory>(new_factory.release());
 }
 
 bool CompositeDataSourceFactory::AllowRequests() const {
diff --git a/media/base/composite_data_source_factory.h b/media/base/composite_data_source_factory.h
index 9f962d8..0118ce5 100644
--- a/media/base/composite_data_source_factory.h
+++ b/media/base/composite_data_source_factory.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -19,11 +19,11 @@ class MEDIA_EXPORT CompositeDataSourceFactory
   CompositeDataSourceFactory();
   virtual ~CompositeDataSourceFactory();
 
-  // Add factory to this composite. Ownership is transferred here.
-  void AddFactory(DataSourceFactory* factory);
+  // Add factory to this composite.
+  void AddFactory(scoped_ptr<DataSourceFactory> factory);
 
   // DataSourceFactory method.
-  virtual DataSourceFactory* Clone() const OVERRIDE;
+  virtual scoped_ptr<DataSourceFactory> Clone() const OVERRIDE;
 
  protected:
   // AsyncDataSourceFactoryBase methods.
diff --git a/media/base/data_buffer.cc b/media/base/data_buffer.cc
index 31b3c1c..b82de51 100644
--- a/media/base/data_buffer.cc
+++ b/media/base/data_buffer.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -7,8 +7,8 @@
 
 namespace media {
 
-DataBuffer::DataBuffer(uint8* buffer, size_t buffer_size)
-    : data_(buffer),
+DataBuffer::DataBuffer(scoped_array<uint8> buffer, size_t buffer_size)
+    : data_(buffer.Pass()),
       buffer_size_(buffer_size),
       data_size_(buffer_size) {
 }
diff --git a/media/base/data_buffer.h b/media/base/data_buffer.h
index bb010f3..6c5c8a9 100644
--- a/media/base/data_buffer.h
+++ b/media/base/data_buffer.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -17,9 +17,8 @@ namespace media {
 
 class MEDIA_EXPORT DataBuffer : public Buffer {
  public:
-  // Takes ownership of the passed |buffer|, assumes valid data of size
-  // |buffer_size|.
-  DataBuffer(uint8* buffer, size_t buffer_size);
+  // Assumes valid data of size |buffer_size|.
+  DataBuffer(scoped_array<uint8> buffer, size_t buffer_size);
 
   // Allocates buffer of size |buffer_size|. If |buffer_size| is 0, |data_| is
   // set to a NULL ptr.
diff --git a/media/base/filter_collection.cc b/media/base/filter_collection.cc
index ed2339f..42f42d0 100644
--- a/media/base/filter_collection.cc
+++ b/media/base/filter_collection.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -12,9 +12,9 @@ FilterCollection::FilterCollection() {}
 
 FilterCollection::~FilterCollection() {}
 
-void FilterCollection::SetDemuxerFactory(DemuxerFactory* factory) {
-  DCHECK(factory);
-  demuxer_factory_.reset(factory);
+void FilterCollection::SetDemuxerFactory(scoped_ptr<DemuxerFactory> factory) {
+  DCHECK(factory.get());
+  demuxer_factory_ = factory.Pass();
 }
 
 DemuxerFactory* FilterCollection::GetDemuxerFactory() {
diff --git a/media/base/filter_collection.h b/media/base/filter_collection.h
index edf6b29..f129723 100644
--- a/media/base/filter_collection.h
+++ b/media/base/filter_collection.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -21,8 +21,7 @@ class MEDIA_EXPORT FilterCollection {
   ~FilterCollection();
 
   // DemuxerFactory accessor methods.
-  // FilterCollection takes ownership of the factory here.
-  void SetDemuxerFactory(DemuxerFactory* factory);
+  void SetDemuxerFactory(scoped_ptr<DemuxerFactory> factory);
   DemuxerFactory* GetDemuxerFactory();
 
   // Adds a filter to the collection.
diff --git a/media/base/filter_factories.h b/media/base/filter_factories.h
index 8b27c11..6158ff4 100644
--- a/media/base/filter_factories.h
+++ b/media/base/filter_factories.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -28,7 +28,7 @@ class MEDIA_EXPORT DataSourceFactory {
 
   // Makes a copy of this factory.
   // NOTE: Pending requests are not cloned.
-  virtual DataSourceFactory* Clone() const = 0;
+  virtual scoped_ptr<DataSourceFactory> Clone() const = 0;
 };
 
 class Demuxer;
@@ -46,7 +46,7 @@ class MEDIA_EXPORT DemuxerFactory {
 
   // Makes a copy of this factory.
   // NOTE: Pending requests are not cloned.
-  virtual DemuxerFactory* Clone() const = 0;
+  virtual scoped_ptr<DemuxerFactory> Clone() const = 0;
 };
 
 }  // namespace media
diff --git a/media/base/media_log.cc b/media/base/media_log.cc
index ea61682..d9ac529 100644
--- a/media/base/media_log.cc
+++ b/media/base/media_log.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -150,81 +150,81 @@ MediaLog::MediaLog() {
 
 MediaLog::~MediaLog() {}
 
-void MediaLog::AddEvent(MediaLogEvent* event) {
-  scoped_ptr<MediaLogEvent> e(event);
+void MediaLog::AddEvent(scoped_ptr<MediaLogEvent> event) {
 }
 
-MediaLogEvent* MediaLog::CreateEvent(MediaLogEvent::Type type) {
+scoped_ptr<MediaLogEvent> MediaLog::CreateEvent(MediaLogEvent::Type type) {
   scoped_ptr<MediaLogEvent> event(new MediaLogEvent);
   event->id = id_;
   event->type = type;
   event->time = base::Time::Now();
-  return event.release();
+  return event.Pass();
 }
 
-MediaLogEvent* MediaLog::CreateBooleanEvent(MediaLogEvent::Type type,
-                                            const char* property, bool value) {
+scoped_ptr<MediaLogEvent> MediaLog::CreateBooleanEvent(
+    MediaLogEvent::Type type, const char* property, bool value) {
   scoped_ptr<MediaLogEvent> event(CreateEvent(type));
   event->params.SetBoolean(property, value);
-  return event.release();
+  return event.Pass();
 }
 
-MediaLogEvent* MediaLog::CreateIntegerEvent(MediaLogEvent::Type type,
-                                            const char* property, int64 value) {
+scoped_ptr<MediaLogEvent> MediaLog::CreateIntegerEvent(
+    MediaLogEvent::Type type, const char* property, int64 value) {
   scoped_ptr<MediaLogEvent> event(CreateEvent(type));
   event->params.SetInteger(property, value);
-  return event.release();
+  return event.Pass();
 }
 
-MediaLogEvent* MediaLog::CreateTimeEvent(MediaLogEvent::Type type,
-                                         const char* property,
-                                         base::TimeDelta value) {
+scoped_ptr<MediaLogEvent> MediaLog::CreateTimeEvent(
+    MediaLogEvent::Type type, const char* property, base::TimeDelta value) {
   scoped_ptr<MediaLogEvent> event(CreateEvent(type));
   event->params.SetDouble(property, value.InSecondsF());
-  return event.release();
+  return event.Pass();
 }
 
-MediaLogEvent* MediaLog::CreateLoadEvent(const std::string& url) {
+scoped_ptr<MediaLogEvent> MediaLog::CreateLoadEvent(const std::string& url) {
   scoped_ptr<MediaLogEvent> event(CreateEvent(MediaLogEvent::LOAD));
   event->params.SetString("url", url);
-  return event.release();
+  return event.Pass();
 }
 
-MediaLogEvent* MediaLog::CreateSeekEvent(float seconds) {
+scoped_ptr<MediaLogEvent> MediaLog::CreateSeekEvent(float seconds) {
   scoped_ptr<MediaLogEvent> event(CreateEvent(MediaLogEvent::SEEK));
   event->params.SetDouble("seek_target", seconds);
-  return event.release();
+  return event.Pass();
 }
 
-MediaLogEvent* MediaLog::CreatePipelineStateChangedEvent(
+scoped_ptr<MediaLogEvent> MediaLog::CreatePipelineStateChangedEvent(
     PipelineImpl::State state) {
   scoped_ptr<MediaLogEvent> event(
       CreateEvent(MediaLogEvent::PIPELINE_STATE_CHANGED));
   event->params.SetString("pipeline_state", PipelineStateToString(state));
-  return event.release();
+  return event.Pass();
 }
 
-MediaLogEvent* MediaLog::CreatePipelineErrorEvent(PipelineStatus error) {
+scoped_ptr<MediaLogEvent> MediaLog::CreatePipelineErrorEvent(
+    PipelineStatus error) {
   scoped_ptr<MediaLogEvent> event(CreateEvent(MediaLogEvent::PIPELINE_ERROR));
   event->params.SetString("pipeline_error", PipelineStatusToString(error));
-  return event.release();
+  return event.Pass();
 }
 
-MediaLogEvent* MediaLog::CreateVideoSizeSetEvent(size_t width, size_t height) {
+scoped_ptr<MediaLogEvent> MediaLog::CreateVideoSizeSetEvent(
+    size_t width, size_t height) {
   scoped_ptr<MediaLogEvent> event(CreateEvent(MediaLogEvent::VIDEO_SIZE_SET));
   event->params.SetInteger("width", width);
   event->params.SetInteger("height", height);
-  return event.release();
+  return event.Pass();
 }
 
-MediaLogEvent* MediaLog::CreateBufferedExtentsChangedEvent(
+scoped_ptr<MediaLogEvent> MediaLog::CreateBufferedExtentsChangedEvent(
     size_t start, size_t current, size_t end) {
   scoped_ptr<MediaLogEvent> event(
       CreateEvent(MediaLogEvent::BUFFERED_EXTENTS_CHANGED));
   event->params.SetInteger("buffer_start", start);
   event->params.SetInteger("buffer_current", current);
   event->params.SetInteger("buffer_end", end);
-  return event.release();
+  return event.Pass();
 }
 
 void MediaLog::QueueStatisticsUpdatedEvent(PipelineStatistics stats) {
@@ -255,7 +255,7 @@ void MediaLog::AddStatisticsUpdatedEvent() {
                            last_statistics_.video_frames_decoded);
   event->params.SetInteger("video_frames_dropped",
                            last_statistics_.video_frames_dropped);
-  AddEvent(event.release());
+  AddEvent(event.Pass());
   stats_update_pending_ = false;
 }
 
diff --git a/media/base/media_log.h b/media/base/media_log.h
index 9f5e668..236c533 100644
--- a/media/base/media_log.h
+++ b/media/base/media_log.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -26,24 +26,25 @@ class MEDIA_EXPORT MediaLog : public base::RefCountedThreadSafe<MediaLog> {
 
   // Add an event to this log. Overriden by inheritors to actually do something
   // with it.
-  // Takes ownership of |event|.
-  virtual void AddEvent(MediaLogEvent* event);
+  virtual void AddEvent(scoped_ptr<MediaLogEvent> event);
 
   // Helper methods to create events and their parameters.
-  MediaLogEvent* CreateEvent(MediaLogEvent::Type type);
-  MediaLogEvent* CreateBooleanEvent(MediaLogEvent::Type type,
-                                    const char* property, bool value);
-  MediaLogEvent* CreateIntegerEvent(MediaLogEvent::Type type,
-                                    const char* property, int64 value);
-  MediaLogEvent* CreateTimeEvent(MediaLogEvent::Type type,
-                                 const char* property, base::TimeDelta value);
-  MediaLogEvent* CreateLoadEvent(const std::string& url);
-  MediaLogEvent* CreateSeekEvent(float seconds);
-  MediaLogEvent* CreatePipelineStateChangedEvent(PipelineImpl::State state);
-  MediaLogEvent* CreatePipelineErrorEvent(PipelineStatus error);
-  MediaLogEvent* CreateVideoSizeSetEvent(size_t width, size_t height);
-  MediaLogEvent* CreateBufferedExtentsChangedEvent(size_t start, size_t current,
-                                                   size_t end);
+  scoped_ptr<MediaLogEvent> CreateEvent(MediaLogEvent::Type type);
+  scoped_ptr<MediaLogEvent> CreateBooleanEvent(
+      MediaLogEvent::Type type, const char* property, bool value);
+  scoped_ptr<MediaLogEvent> CreateIntegerEvent(
+      MediaLogEvent::Type type, const char* property, int64 value);
+  scoped_ptr<MediaLogEvent> CreateTimeEvent(
+      MediaLogEvent::Type type, const char* property, base::TimeDelta value);
+  scoped_ptr<MediaLogEvent> CreateLoadEvent(const std::string& url);
+  scoped_ptr<MediaLogEvent> CreateSeekEvent(float seconds);
+  scoped_ptr<MediaLogEvent> CreatePipelineStateChangedEvent(
+      PipelineImpl::State state);
+  scoped_ptr<MediaLogEvent> CreatePipelineErrorEvent(PipelineStatus error);
+  scoped_ptr<MediaLogEvent> CreateVideoSizeSetEvent(
+      size_t width, size_t height);
+  scoped_ptr<MediaLogEvent> CreateBufferedExtentsChangedEvent(
+      size_t start, size_t current, size_t end);
 
   // Called when the pipeline statistics have been updated.
   // This gets called every frame, so we send the most recent stats after 500ms.
diff --git a/media/base/mock_filters.cc b/media/base/mock_filters.cc
index a406620..44c0062 100644
--- a/media/base/mock_filters.cc
+++ b/media/base/mock_filters.cc
@@ -1,10 +1,11 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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/mock_filters.h"
 
 #include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
 #include "media/base/filter_host.h"
 
 using ::testing::_;
@@ -65,8 +66,8 @@ void MockDemuxerFactory::RunBuildCallback(const std::string& url,
   callback.Run(status_, NULL);
 }
 
-DemuxerFactory* MockDemuxerFactory::Clone() const {
-  return new MockDemuxerFactory(demuxer_.get());
+scoped_ptr<DemuxerFactory> MockDemuxerFactory::Clone() const {
+  return scoped_ptr<DemuxerFactory>(new MockDemuxerFactory(demuxer_.get()));
 }
 
 MockDemuxer::MockDemuxer()
@@ -124,33 +125,36 @@ MockFilterCollection::MockFilterCollection()
 
 MockFilterCollection::~MockFilterCollection() {}
 
-FilterCollection* MockFilterCollection::filter_collection(
+scoped_ptr<FilterCollection> MockFilterCollection::filter_collection(
     bool include_demuxer,
     bool run_build_callback,
     bool run_build,
     PipelineStatus build_status) const {
-  FilterCollection* collection = new FilterCollection();
+  scoped_ptr<FilterCollection> collection(new FilterCollection());
 
-  MockDemuxerFactory* demuxer_factory =
-      new MockDemuxerFactory(include_demuxer ? demuxer_ : NULL);
+  scoped_ptr<MockDemuxerFactory> demuxer_factory(
+      new MockDemuxerFactory(include_demuxer ? demuxer_ : NULL));
 
   if (build_status != PIPELINE_OK)
     demuxer_factory->SetError(build_status);
 
   if (run_build_callback) {
     ON_CALL(*demuxer_factory, Build(_, _)).WillByDefault(Invoke(
-        demuxer_factory, &MockDemuxerFactory::RunBuildCallback));
+        demuxer_factory.get(), &MockDemuxerFactory::RunBuildCallback));
   }  // else ignore Build calls.
 
   if (run_build)
     EXPECT_CALL(*demuxer_factory, Build(_, _));
 
-  collection->SetDemuxerFactory(demuxer_factory);
+  // TODO(fischman): replace the extra scoped_ptr+release() with Pass() when
+  // http://crbug.com/109026 is fixed.
+  collection->SetDemuxerFactory(scoped_ptr<DemuxerFactory>(
+      demuxer_factory.release()));
   collection->AddVideoDecoder(video_decoder_);
   collection->AddAudioDecoder(audio_decoder_);
   collection->AddVideoRenderer(video_renderer_);
   collection->AddAudioRenderer(audio_renderer_);
-  return collection;
+  return collection.Pass();
 }
 
 void RunFilterCallback(::testing::Unused, const base::Closure& callback) {
diff --git a/media/base/mock_filters.h b/media/base/mock_filters.h
index 5f8a5d7..22a0ce59 100644
--- a/media/base/mock_filters.h
+++ b/media/base/mock_filters.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 //
@@ -148,7 +148,7 @@ class MockDemuxerFactory : public DemuxerFactory {
   // DemuxerFactory methods.
   MOCK_METHOD2(Build, void(const std::string& url,
                            const BuildCallback& callback));
-  virtual DemuxerFactory* Clone() const;
+  virtual scoped_ptr<DemuxerFactory> Clone() const;
 
  private:
   scoped_refptr<MockDemuxer> demuxer_;
@@ -294,14 +294,13 @@ class MockFilterCollection {
   MockVideoRenderer* video_renderer() const { return video_renderer_; }
   MockAudioRenderer* audio_renderer() const { return audio_renderer_; }
 
-  FilterCollection* filter_collection() const {
-    return filter_collection(true, true, true, PIPELINE_OK);
+  scoped_ptr<FilterCollection> filter_collection() const {
+    return filter_collection(true, true, true, PIPELINE_OK).Pass();
   }
 
-  FilterCollection* filter_collection(bool include_demuxer,
-                                      bool run_build_callback,
-                                      bool run_build,
-                                      PipelineStatus build_status) const;
+  scoped_ptr<FilterCollection> filter_collection(
+      bool include_demuxer, bool run_build_callback, bool run_build,
+      PipelineStatus build_status) const;
 
  private:
   scoped_refptr<MockDemuxer> demuxer_;
diff --git a/media/base/pipeline.h b/media/base/pipeline.h
index cc38c4b..7d382d0 100644
--- a/media/base/pipeline.h
+++ b/media/base/pipeline.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -50,8 +50,7 @@ class MEDIA_EXPORT Pipeline : public base::RefCountedThreadSafe<Pipeline> {
   // The parameter specifies the type of event that is being signaled.
   typedef base::Callback<void(NetworkEvent)> NetworkEventCB;
 
-  // Initializes pipeline. Pipeline takes ownership of all callbacks passed
-  // into this method.
+  // Initializes pipeline.
   // |ended_callback| will be executed when the media reaches the end.
   // |error_callback_| will be executed upon an error in the pipeline.
   // |network_callback_| will be executed when there's a network event.
@@ -70,7 +69,7 @@ class MEDIA_EXPORT Pipeline : public base::RefCountedThreadSafe<Pipeline> {
   // This method is asynchronous and can execute a callback when completed.
   // If the caller provides a |start_callback|, it will be called when the
   // pipeline initialization completes.
-  virtual bool Start(FilterCollection* filter_collection,
+  virtual bool Start(scoped_ptr<FilterCollection> filter_collection,
                      const std::string& url,
                      const PipelineStatusCB& start_callback) = 0;
 
diff --git a/media/base/pipeline_impl.cc b/media/base/pipeline_impl.cc
index 5ea444c..7f709e4 100644
--- a/media/base/pipeline_impl.cc
+++ b/media/base/pipeline_impl.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 //
@@ -98,11 +98,10 @@ void PipelineImpl::Init(const PipelineStatusCB& ended_callback,
 }
 
 // Creates the PipelineInternal and calls it's start method.
-bool PipelineImpl::Start(FilterCollection* collection,
+bool PipelineImpl::Start(scoped_ptr<FilterCollection> collection,
                          const std::string& url,
                          const PipelineStatusCB& start_callback) {
   base::AutoLock auto_lock(lock_);
-  scoped_ptr<FilterCollection> filter_collection(collection);
 
   if (running_) {
     VLOG(1) << "Media pipeline is already running";
@@ -118,7 +117,7 @@ bool PipelineImpl::Start(FilterCollection* collection,
   message_loop_->PostTask(
       FROM_HERE,
       base::Bind(&PipelineImpl::StartTask, this,
-                 filter_collection.release(),
+                 base::Passed(&collection),
                  url,
                  start_callback));
   return true;
@@ -626,12 +625,12 @@ void PipelineImpl::OnUpdateStatistics(const PipelineStatistics& stats) {
   media_log_->QueueStatisticsUpdatedEvent(statistics_);
 }
 
-void PipelineImpl::StartTask(FilterCollection* filter_collection,
+void PipelineImpl::StartTask(scoped_ptr<FilterCollection> filter_collection,
                              const std::string& url,
                              const PipelineStatusCB& start_callback) {
   DCHECK_EQ(MessageLoop::current(), message_loop_);
   DCHECK_EQ(kCreated, state_);
-  filter_collection_.reset(filter_collection);
+  filter_collection_ = filter_collection.Pass();
   url_ = url;
   seek_callback_ = start_callback;
 
diff --git a/media/base/pipeline_impl.h b/media/base/pipeline_impl.h
index be55291..c7a8e9f 100644
--- a/media/base/pipeline_impl.h
+++ b/media/base/pipeline_impl.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -107,7 +107,7 @@ class MEDIA_EXPORT PipelineImpl
   virtual void Init(const PipelineStatusCB& ended_callback,
                     const PipelineStatusCB& error_callback,
                     const NetworkEventCB& network_callback) OVERRIDE;
-  virtual bool Start(FilterCollection* filter_collection,
+  virtual bool Start(scoped_ptr<FilterCollection> filter_collection,
                      const std::string& uri,
                      const PipelineStatusCB& start_callback) OVERRIDE;
   virtual void Stop(const PipelineStatusCB& stop_callback) OVERRIDE;
@@ -231,7 +231,7 @@ class MEDIA_EXPORT PipelineImpl
   // The following "task" methods correspond to the public methods, but these
   // methods are run as the result of posting a task to the PipelineInternal's
   // message loop.
-  void StartTask(FilterCollection* filter_collection,
+  void StartTask(scoped_ptr<FilterCollection> filter_collection,
                  const std::string& url,
                  const PipelineStatusCB& start_callback);
 
diff --git a/media/base/pipeline_impl_unittest.cc b/media/base/pipeline_impl_unittest.cc
index e27bdda..73b62b5 100644
--- a/media/base/pipeline_impl_unittest.cc
+++ b/media/base/pipeline_impl_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -205,7 +205,7 @@ class PipelineImplTest : public ::testing::Test {
     pipeline_->Start(mocks_->filter_collection(true,
                                                true,
                                                true,
-                                               build_status),
+                                               build_status).Pass(),
                      "",
                      base::Bind(&CallbackHelper::OnStart,
                                 base::Unretained(&callbacks_)));
@@ -328,7 +328,7 @@ TEST_F(PipelineImplTest, NeverInitializes) {
   pipeline_->Start(mocks_->filter_collection(false,
                                              false,
                                              true,
-                                             PIPELINE_OK),
+                                             PIPELINE_OK).Pass(),
                    "",
                    base::Bind(&CallbackHelper::OnStart,
                               base::Unretained(&callbacks_)));
@@ -352,12 +352,9 @@ TEST_F(PipelineImplTest, RequiredFilterMissing) {
   EXPECT_CALL(callbacks_, OnStart(PIPELINE_ERROR_REQUIRED_FILTER_MISSING));
 
   // Create a filter collection with missing filter.
-  FilterCollection* collection =
-      mocks_->filter_collection(false,
-                                true,
-                                true,
-                                PIPELINE_ERROR_REQUIRED_FILTER_MISSING);
-  pipeline_->Start(collection, "",
+  scoped_ptr<FilterCollection> collection(mocks_->filter_collection(
+      false, true, true, PIPELINE_ERROR_REQUIRED_FILTER_MISSING));
+  pipeline_->Start(collection.Pass(), "",
                    base::Bind(&CallbackHelper::OnStart,
                               base::Unretained(&callbacks_)));
   message_loop_.RunAllPending();
diff --git a/media/base/test_data_util.cc b/media/base/test_data_util.cc
index 45a3735..a7fb78e 100644
--- a/media/base/test_data_util.cc
+++ b/media/base/test_data_util.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -42,7 +42,7 @@ void ReadTestDataFile(const std::string& name, scoped_refptr<Buffer>* buffer) {
   scoped_array<uint8> buf;
   int buf_size;
   ReadTestDataFile(name, &buf, &buf_size);
-  *buffer = new DataBuffer(buf.release(), buf_size);
+  *buffer = new DataBuffer(buf.Pass(), buf_size);
 }
 
 }  // namespace media