net: Implement canceling of all async operations in FileStream.

Canceling of async operations allows to not wait for their completion
in FileStream's destructor. Other related changes include:

- Got rid of FileStream::Close() and FileStream::CloseSync() methods because
reuse of FileStream object doesn't make much sense, it should be destroyed
instead.

- Changed FileStream to always acquire ownership of the PlatformFile it was
given. Fixed usages of FileStream where no ownership was assumed, introduced
new helper functions in base/platform_file.h on the way.

- FileStream's destructor now always closes the file. If file was opened with
PLATFORM_FILE_ASYNC then actual closing is done asynchronously, destructor
doesn't wait for that and returns immediately. When file was opened without
PLATFORM_FILE_ASYNC closing is done synchronously and the thread doing that
should be allowed to do IO operations.

- Implementation of FileStream is refactored. FileStream is now just a wrapper
around internal object that does all actual work and that can be easily
orphaned in the destructor to not block on the actual file descriptor closing.
All platform-independent code is extracted into a special file and amount of
platform-dependent code is minimized.


BUG=115067, 112474
TEST=net_unittests

Review URL: https://chromiumcodereview.appspot.com/10701050

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@166091 0039d316-1c4b-4281-b951-d872f2087c98

16 files changed, 1186 insertions, 2040 deletions

diff --git a/net/base/file_stream.cc b/net/base/file_stream.cc
index df18ad0..05f1460 100644
--- a/net/base/file_stream.cc
+++ b/net/base/file_stream.cc
@@ -4,99 +4,261 @@
 
 #include "net/base/file_stream.h"
 
+#include "base/location.h"
+#include "base/message_loop_proxy.h"
+#include "base/task_runner_util.h"
+#include "base/threading/thread_restrictions.h"
+#include "base/threading/worker_pool.h"
+#include "net/base/file_stream_context.h"
+#include "net/base/file_stream_net_log_parameters.h"
+#include "net/base/net_errors.h"
+
 namespace net {
 
-FileStream::FileStream(net::NetLog* net_log)
-    : impl_(net_log) {
+FileStream::FileStream(NetLog* net_log)
+      /* To allow never opened stream to be destroyed on any thread we set flags
+         as if stream was opened asynchronously. */
+    : open_flags_(base::PLATFORM_FILE_ASYNC),
+      bound_net_log_(BoundNetLog::Make(net_log, NetLog::SOURCE_FILESTREAM)),
+      context_(new Context(bound_net_log_)) {
+  bound_net_log_.BeginEvent(NetLog::TYPE_FILE_STREAM_ALIVE);
 }
 
-FileStream::FileStream(
-    base::PlatformFile file, int flags, net::NetLog* net_log)
-    : impl_(file, flags, net_log) {
+FileStream::FileStream(base::PlatformFile file, int flags, NetLog* net_log)
+    : open_flags_(flags),
+      bound_net_log_(BoundNetLog::Make(net_log, NetLog::SOURCE_FILESTREAM)),
+      context_(new Context(file, bound_net_log_, open_flags_)) {
+  bound_net_log_.BeginEvent(NetLog::TYPE_FILE_STREAM_ALIVE);
 }
 
 FileStream::~FileStream() {
-}
-
-void FileStream::Close(const CompletionCallback& callback) {
-  impl_.Close(callback);
-}
+  if (!is_async()) {
+    base::ThreadRestrictions::AssertIOAllowed();
+    context_->CloseSync();
+    context_.reset();
+  } else {
+    context_.release()->Orphan();
+  }
 
-void FileStream::CloseSync() {
-  impl_.CloseSync();
+  bound_net_log_.EndEvent(NetLog::TYPE_FILE_STREAM_ALIVE);
 }
 
 int FileStream::Open(const FilePath& path, int open_flags,
                      const CompletionCallback& callback) {
-  return impl_.Open(path, open_flags, callback);
+  if (IsOpen()) {
+    DLOG(FATAL) << "File is already open!";
+    return ERR_UNEXPECTED;
+  }
+
+  open_flags_ = open_flags;
+  DCHECK(is_async());
+  context_->OpenAsync(path, open_flags, callback);
+  return ERR_IO_PENDING;
 }
 
 int FileStream::OpenSync(const FilePath& path, int open_flags) {
-  return impl_.OpenSync(path, open_flags);
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  if (IsOpen()) {
+    DLOG(FATAL) << "File is already open!";
+    return ERR_UNEXPECTED;
+  }
+
+  open_flags_ = open_flags;
+  // TODO(satorux): Put a DCHECK once all async clients are migrated
+  // to use Open(). crbug.com/114783
+  //
+  // DCHECK(!is_async());
+  return context_->OpenSync(path, open_flags_);
 }
 
 bool FileStream::IsOpen() const {
-  return impl_.IsOpen();
+  return context_->file() != base::kInvalidPlatformFileValue;
 }
 
-int FileStream::Seek(Whence whence, int64 offset,
+int FileStream::Seek(Whence whence,
+                     int64 offset,
                      const Int64CompletionCallback& callback) {
-  return impl_.Seek(whence, offset, callback);
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  // Make sure we're async.
+  DCHECK(is_async());
+  context_->SeekAsync(whence, offset, callback);
+  return ERR_IO_PENDING;
 }
 
 int64 FileStream::SeekSync(Whence whence, int64 offset) {
-  return impl_.SeekSync(whence, offset);
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  // If we're in async, make sure we don't have a request in flight.
+  DCHECK(!is_async() || !context_->async_in_progress());
+  return context_->SeekSync(whence, offset);
 }
 
 int64 FileStream::Available() {
-  return impl_.Available();
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  int64 cur_pos = SeekSync(FROM_CURRENT, 0);
+  if (cur_pos < 0)
+    return cur_pos;
+
+  int64 size = context_->GetFileSize();
+  if (size < 0)
+    return size;
+
+  DCHECK_GT(size, cur_pos);
+  return size - cur_pos;
 }
 
-int FileStream::Read(
-    IOBuffer* in_buf, int buf_len, const CompletionCallback& callback) {
-  return impl_.Read(in_buf, buf_len, callback);
+int FileStream::Read(IOBuffer* buf,
+                     int buf_len,
+                     const CompletionCallback& callback) {
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  // read(..., 0) will return 0, which indicates end-of-file.
+  DCHECK_GT(buf_len, 0);
+  DCHECK(open_flags_ & base::PLATFORM_FILE_READ);
+  DCHECK(is_async());
+
+  return context_->ReadAsync(buf, buf_len, callback);
 }
 
 int FileStream::ReadSync(char* buf, int buf_len) {
-  return impl_.ReadSync(buf, buf_len);
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  DCHECK(!is_async());
+  // read(..., 0) will return 0, which indicates end-of-file.
+  DCHECK_GT(buf_len, 0);
+  DCHECK(open_flags_ & base::PLATFORM_FILE_READ);
+
+  return context_->ReadSync(buf, buf_len);
 }
 
 int FileStream::ReadUntilComplete(char *buf, int buf_len) {
-  return impl_.ReadUntilComplete(buf, buf_len);
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  int to_read = buf_len;
+  int bytes_total = 0;
+
+  do {
+    int bytes_read = ReadSync(buf, to_read);
+    if (bytes_read <= 0) {
+      if (bytes_total == 0)
+        return bytes_read;
+
+      return bytes_total;
+    }
+
+    bytes_total += bytes_read;
+    buf += bytes_read;
+    to_read -= bytes_read;
+  } while (bytes_total < buf_len);
+
+  return bytes_total;
 }
 
-int FileStream::Write(
-    IOBuffer* buf, int buf_len, const CompletionCallback& callback) {
-  return impl_.Write(buf, buf_len, callback);
+int FileStream::Write(IOBuffer* buf,
+                      int buf_len,
+                      const CompletionCallback& callback) {
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  DCHECK(is_async());
+  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
+  // write(..., 0) will return 0, which indicates end-of-file.
+  DCHECK_GT(buf_len, 0);
+
+  return context_->WriteAsync(buf, buf_len, callback);
 }
 
 int FileStream::WriteSync(const char* buf, int buf_len) {
-  return impl_.WriteSync(buf, buf_len);
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  DCHECK(!is_async());
+  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
+  // write(..., 0) will return 0, which indicates end-of-file.
+  DCHECK_GT(buf_len, 0);
+
+  return context_->WriteSync(buf, buf_len);
 }
 
 int64 FileStream::Truncate(int64 bytes) {
-  return impl_.Truncate(bytes);
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  // We'd better be open for writing.
+  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
+
+  // Seek to the position to truncate from.
+  int64 seek_position = SeekSync(FROM_BEGIN, bytes);
+  if (seek_position != bytes)
+    return ERR_UNEXPECTED;
+
+  // And truncate the file.
+  return context_->Truncate(bytes);
 }
 
 int FileStream::Flush(const CompletionCallback& callback) {
-  return impl_.Flush(callback);
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
+  // Make sure we're async.
+  DCHECK(is_async());
+
+  context_->FlushAsync(callback);
+  return ERR_IO_PENDING;
 }
 
 int FileStream::FlushSync() {
-  return impl_.FlushSync();
+  base::ThreadRestrictions::AssertIOAllowed();
+
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
+  return context_->FlushSync();
 }
 
 void FileStream::EnableErrorStatistics() {
-  impl_.EnableErrorStatistics();
+  context_->set_record_uma(true);
 }
 
-void FileStream::SetBoundNetLogSource(
-    const net::BoundNetLog& owner_bound_net_log) {
-  impl_.SetBoundNetLogSource(owner_bound_net_log);
+void FileStream::SetBoundNetLogSource(const BoundNetLog& owner_bound_net_log) {
+  if ((owner_bound_net_log.source().id == NetLog::Source::kInvalidId) &&
+      (bound_net_log_.source().id == NetLog::Source::kInvalidId)) {
+    // Both |BoundNetLog|s are invalid.
+    return;
+  }
+
+  // Should never connect to itself.
+  DCHECK_NE(bound_net_log_.source().id, owner_bound_net_log.source().id);
+
+  bound_net_log_.AddEvent(NetLog::TYPE_FILE_STREAM_BOUND_TO_OWNER,
+      owner_bound_net_log.source().ToEventParametersCallback());
+
+  owner_bound_net_log.AddEvent(NetLog::TYPE_FILE_STREAM_SOURCE,
+      bound_net_log_.source().ToEventParametersCallback());
 }
 
 base::PlatformFile FileStream::GetPlatformFileForTesting() {
-  return impl_.GetPlatformFileForTesting();
+  return context_->file();
 }
 
 }  // namespace net
diff --git a/net/base/file_stream.h b/net/base/file_stream.h
index f4cfff2..5c64792 100644
--- a/net/base/file_stream.h
+++ b/net/base/file_stream.h
@@ -15,11 +15,6 @@
 #include "net/base/file_stream_whence.h"
 #include "net/base/net_export.h"
 #include "net/base/net_log.h"
-#if defined(OS_WIN)
-#include "net/base/file_stream_win.h"
-#elif defined(OS_POSIX)
-#include "net/base/file_stream_posix.h"
-#endif
 
 class FilePath;
 
@@ -39,32 +34,13 @@ class NET_EXPORT FileStream {
   // opened.
   // |net_log| is the net log pointer to use to create a |BoundNetLog|.  May be
   // NULL if logging is not needed.
-  // The already opened file will not be automatically closed when FileStream
-  // is destructed.
+  // Note: the new FileStream object takes ownership of the PlatformFile and
+  // will close it on destruction.
   FileStream(base::PlatformFile file, int flags, net::NetLog* net_log);
 
-  // If the file stream was opened with Open() or OpenSync(), the underlying
-  // file will be closed automatically by the destructor, if not closed
-  // manually.
+  // The underlying file is closed automatically.
   virtual ~FileStream();
 
-  // Call this method to close the FileStream, which was previously opened in
-  // the async mode (PLATFORM_FILE_ASYNC) asynchronously.
-  //
-  // Once the operation is done, |callback| will be run on the thread where
-  // Close() was called, with OK (i.e. an error is not propagated just like
-  // CloseSync() does not).
-  //
-  // It is not OK to call Close() multiple times. The behavior is not defined.
-  // Note that there must never be any pending async operations.
-  virtual void Close(const CompletionCallback& callback);
-
-  // Call this method to close the FileStream synchronously.
-  // It is OK to call CloseSync() multiple times.  Redundant calls are
-  // ignored. Note that if there are any pending async operations, they'll
-  // be aborted.
-  virtual void CloseSync();
-
   // Call this method to open the FileStream asynchronously.  The remaining
   // methods cannot be used unless the file is opened successfully. Returns
   // ERR_IO_PENDING if the operation is started. If the operation cannot be
@@ -237,11 +213,20 @@ class NET_EXPORT FileStream {
   base::PlatformFile GetPlatformFileForTesting();
 
  private:
-#if defined(OS_WIN)
-  FileStreamWin impl_;
-#elif defined(OS_POSIX)
-  FileStreamPosix impl_;
-#endif
+  class Context;
+
+  bool is_async() const { return !!(open_flags_ & base::PLATFORM_FILE_ASYNC); }
+
+  int open_flags_;
+  net::BoundNetLog bound_net_log_;
+
+  // Context performing I/O operations. It was extracted into separate class
+  // to perform asynchronous operations because FileStream can be destroyed
+  // before completion of async operation. Also if async FileStream is destroyed
+  // without explicit closing file should be closed asynchronously without
+  // delaying FileStream's destructor. To perform all that separate object is
+  // necessary.
+  scoped_ptr<Context> context_;
 
   DISALLOW_COPY_AND_ASSIGN(FileStream);
 };
diff --git a/net/base/file_stream_context.cc b/net/base/file_stream_context.cc
new file mode 100644
index 0000000..1ed7ef6
--- /dev/null
+++ b/net/base/file_stream_context.cc
@@ -0,0 +1,231 @@
+// 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 "net/base/file_stream_context.h"
+
+#include "base/location.h"
+#include "base/message_loop_proxy.h"
+#include "base/task_runner_util.h"
+#include "base/threading/thread_restrictions.h"
+#include "base/threading/worker_pool.h"
+#include "net/base/file_stream_net_log_parameters.h"
+#include "net/base/net_errors.h"
+
+namespace {
+
+void CallInt64ToInt(const net::CompletionCallback& callback, int64 result) {
+  callback.Run(static_cast<int>(result));
+}
+
+}
+
+namespace net {
+
+void FileStream::Context::Orphan() {
+  DCHECK(!orphaned_);
+
+  orphaned_ = true;
+  if (file_ != base::kInvalidPlatformFileValue)
+    bound_net_log_.EndEvent(NetLog::TYPE_FILE_STREAM_OPEN);
+
+  if (!async_in_progress_) {
+    CloseAndDelete();
+  } else if (file_ != base::kInvalidPlatformFileValue) {
+    CancelIo(file_);
+  }
+}
+
+void FileStream::Context::OpenAsync(const FilePath& path,
+                                    int open_flags,
+                                    const CompletionCallback& callback) {
+  DCHECK(!async_in_progress_);
+
+  BeginOpenEvent(path);
+
+  const bool posted = base::PostTaskAndReplyWithResult(
+      base::WorkerPool::GetTaskRunner(true /* task_is_slow */),
+      FROM_HERE,
+      base::Bind(&Context::OpenFileImpl,
+                 base::Unretained(this), path, open_flags),
+      base::Bind(&Context::OnOpenCompleted,
+                 base::Unretained(this), callback));
+  DCHECK(posted);
+
+  async_in_progress_ = true;
+}
+
+int FileStream::Context::OpenSync(const FilePath& path, int open_flags) {
+  DCHECK(!async_in_progress_);
+
+  BeginOpenEvent(path);
+  OpenResult result = OpenFileImpl(path, open_flags);
+  file_ = result.file;
+  if (file_ == base::kInvalidPlatformFileValue) {
+    result.error_code = ProcessOpenError(result.error_code);
+  } else {
+    // TODO(satorux): Remove this once all async clients are migrated to use
+    // Open(). crbug.com/114783
+    if (open_flags & base::PLATFORM_FILE_ASYNC)
+      OnAsyncFileOpened();
+  }
+  return result.error_code;
+}
+
+void FileStream::Context::CloseSync() {
+  DCHECK(!async_in_progress_);
+  if (file_ != base::kInvalidPlatformFileValue) {
+    base::ClosePlatformFile(file_);
+    file_ = base::kInvalidPlatformFileValue;
+    bound_net_log_.EndEvent(NetLog::TYPE_FILE_STREAM_OPEN);
+  }
+}
+
+void FileStream::Context::SeekAsync(Whence whence,
+                                    int64 offset,
+                                    const Int64CompletionCallback& callback) {
+  DCHECK(!async_in_progress_);
+
+  const bool posted = base::PostTaskAndReplyWithResult(
+      base::WorkerPool::GetTaskRunner(true /* task is slow */),
+      FROM_HERE,
+      base::Bind(&Context::SeekFileImpl,
+                 base::Unretained(this), whence, offset),
+      base::Bind(&Context::ProcessAsyncResult,
+                 base::Unretained(this), callback, FILE_ERROR_SOURCE_SEEK));
+  DCHECK(posted);
+
+  async_in_progress_ = true;
+}
+
+int64 FileStream::Context::SeekSync(Whence whence, int64 offset) {
+  int64 result = SeekFileImpl(whence, offset);
+  CheckForIOError(&result, FILE_ERROR_SOURCE_SEEK);
+  return result;
+}
+
+void FileStream::Context::FlushAsync(const CompletionCallback& callback) {
+  DCHECK(!async_in_progress_);
+
+  const bool posted = base::PostTaskAndReplyWithResult(
+      base::WorkerPool::GetTaskRunner(true /* task is slow */),
+      FROM_HERE,
+      base::Bind(&Context::FlushFileImpl,
+                 base::Unretained(this)),
+      base::Bind(&Context::ProcessAsyncResult,
+                 base::Unretained(this), IntToInt64(callback),
+                 FILE_ERROR_SOURCE_FLUSH));
+  DCHECK(posted);
+
+  async_in_progress_ = true;
+}
+
+int FileStream::Context::FlushSync() {
+  int64 result = FlushFileImpl();
+  CheckForIOError(&result, FILE_ERROR_SOURCE_FLUSH);
+  return result;
+}
+
+int FileStream::Context::RecordAndMapError(int error,
+                                           FileErrorSource source) const {
+  // The following check is against incorrect use or bug. File descriptor
+  // shouldn't ever be closed outside of FileStream while it still tries to do
+  // something with it.
+  DCHECK(error != ERROR_BAD_FILE);
+  Error net_error = MapSystemError(error);
+
+  if (!orphaned_) {
+    bound_net_log_.AddEvent(NetLog::TYPE_FILE_STREAM_ERROR,
+                            base::Bind(&NetLogFileStreamErrorCallback,
+                                       source, error, net_error));
+  }
+  RecordFileError(error, source, record_uma_);
+  return net_error;
+}
+
+void FileStream::Context::BeginOpenEvent(const FilePath& path) {
+  std::string file_name = path.AsUTF8Unsafe();
+  bound_net_log_.BeginEvent(NetLog::TYPE_FILE_STREAM_OPEN,
+                            NetLog::StringCallback("file_name", &file_name));
+}
+
+FileStream::Context::OpenResult FileStream::Context::OpenFileImpl(
+    const FilePath& path, int open_flags) {
+  OpenResult result;
+  result.error_code = OK;
+  result.file = base::CreatePlatformFile(path, open_flags, NULL, NULL);
+  if (result.file == base::kInvalidPlatformFileValue)
+    result.error_code = GetLastErrno();
+
+  return result;
+}
+
+int FileStream::Context::ProcessOpenError(int error_code) {
+  bound_net_log_.EndEvent(NetLog::TYPE_FILE_STREAM_OPEN);
+  return RecordAndMapError(error_code, FILE_ERROR_SOURCE_OPEN);
+}
+
+void FileStream::Context::OnOpenCompleted(const CompletionCallback& callback,
+                                          OpenResult result) {
+  file_ = result.file;
+  if (file_ == base::kInvalidPlatformFileValue)
+    result.error_code = ProcessOpenError(result.error_code);
+  else if (!orphaned_)
+    OnAsyncFileOpened();
+  OnAsyncCompleted(IntToInt64(callback), result.error_code);
+}
+
+void FileStream::Context::CloseAndDelete() {
+  DCHECK(!async_in_progress_);
+
+  if (file_ == base::kInvalidPlatformFileValue) {
+    delete this;
+  } else {
+    const bool posted = base::WorkerPool::PostTaskAndReply(
+        FROM_HERE,
+        base::Bind(base::IgnoreResult(&base::ClosePlatformFile), file_),
+        base::Bind(&Context::OnCloseCompleted, base::Unretained(this)),
+        true /* task_is_slow */);
+    DCHECK(posted);
+    file_ = base::kInvalidPlatformFileValue;
+  }
+}
+
+void FileStream::Context::OnCloseCompleted() {
+  delete this;
+}
+
+Int64CompletionCallback FileStream::Context::IntToInt64(
+    const CompletionCallback& callback) {
+  return base::Bind(&CallInt64ToInt, callback);
+}
+
+void FileStream::Context::CheckForIOError(int64* result,
+                                          FileErrorSource source) {
+  if (*result < 0)
+    *result = RecordAndMapError(static_cast<int>(*result), source);
+}
+
+void FileStream::Context::ProcessAsyncResult(
+    const Int64CompletionCallback& callback,
+    FileErrorSource source,
+    int64 result) {
+  CheckForIOError(&result, source);
+  OnAsyncCompleted(callback, result);
+}
+
+void FileStream::Context::OnAsyncCompleted(
+    const Int64CompletionCallback& callback,
+    int64 result) {
+  // Reset this before Run() as Run() may issue a new async operation. Also it
+  // should be reset before CloseAsync() because it shouldn't run if any async
+  // operation is in progress.
+  async_in_progress_ = false;
+  if (orphaned_)
+    CloseAndDelete();
+  else
+    callback.Run(result);
+}
+
+}  // namespace net
+
diff --git a/net/base/file_stream_context.h b/net/base/file_stream_context.h
new file mode 100644
index 0000000..244c25f
--- /dev/null
+++ b/net/base/file_stream_context.h
@@ -0,0 +1,230 @@
+// 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.
+
+// This file defines FileStream::Context class.
+// The general design of FileStream is as follows: file_stream.h defines
+// FileStream class which basically is just an "wrapper" not containing any
+// specific implementation details. It re-routes all its method calls to
+// the instance of FileStream::Context (FileStream holds a scoped_ptr to
+// FileStream::Context instance). Context was extracted into a different class
+// to be able to do and finish all async operations even when FileStream
+// instance is deleted. So FileStream's destructor can schedule file
+// closing to be done by Context in WorkerPool and then just return (releasing
+// Context pointer from scoped_ptr) without waiting for actual closing to
+// complete.
+// Implementation of FileStream::Context is divided in two parts: some methods
+// and members are platform-independent and some depend on the platform. This
+// header file contains the complete definition of Context class including all
+// platform-dependent parts (because of that it has a lot of #if-#else
+// branching). Implementations of all platform-independent methods are
+// located in file_stream_context.cc, and all platform-dependent methods are
+// in file_stream_context_{win,posix}.cc. This separation provides better
+// readability of Context's code. And we tried to make as much Context code
+// platform-independent as possible. So file_stream_context_{win,posix}.cc are
+// much smaller than file_stream_context.cc now.
+
+#ifndef NET_BASE_FILE_STREAM_CONTEXT_H_
+#define NET_BASE_FILE_STREAM_CONTEXT_H_
+
+#include "base/message_loop.h"
+#include "base/platform_file.h"
+#include "net/base/completion_callback.h"
+#include "net/base/file_stream.h"
+#include "net/base/file_stream_metrics.h"
+#include "net/base/file_stream_whence.h"
+#include "net/base/net_log.h"
+
+#if defined(OS_POSIX)
+#include <errno.h>
+#endif
+
+class FilePath;
+
+namespace net {
+
+class IOBuffer;
+
+#if defined(OS_WIN)
+class FileStream::Context : public MessageLoopForIO::IOHandler {
+#elif defined(OS_POSIX)
+class FileStream::Context {
+#endif
+ public:
+  ////////////////////////////////////////////////////////////////////////////
+  // Platform-dependent methods implemented in
+  // file_stream_context_{win,posix}.cc.
+  ////////////////////////////////////////////////////////////////////////////
+
+  explicit Context(const BoundNetLog& bound_net_log);
+  Context(base::PlatformFile file,
+          const BoundNetLog& bound_net_log,
+          int open_flags);
+#if defined(OS_WIN)
+  virtual ~Context();
+#elif defined(OS_POSIX)
+  ~Context();
+#endif
+
+  int64 GetFileSize() const;
+
+  int ReadAsync(IOBuffer* buf,
+                int buf_len,
+                const CompletionCallback& callback);
+  int ReadSync(char* buf, int buf_len);
+
+  int WriteAsync(IOBuffer* buf,
+                 int buf_len,
+                 const CompletionCallback& callback);
+  int WriteSync(const char* buf, int buf_len);
+
+  int Truncate(int64 bytes);
+
+  ////////////////////////////////////////////////////////////////////////////
+  // Inline methods.
+  ////////////////////////////////////////////////////////////////////////////
+
+  void set_record_uma(bool value) { record_uma_ = value; }
+  base::PlatformFile file() const { return file_; }
+  bool async_in_progress() const { return async_in_progress_; }
+
+  ////////////////////////////////////////////////////////////////////////////
+  // Platform-independent methods implemented in file_stream_context.cc.
+  ////////////////////////////////////////////////////////////////////////////
+
+  // Destroys the context. It can be deleted in the method or deletion can be
+  // deferred if some asynchronous operation is now in progress or if file is
+  // not closed yet.
+  void Orphan();
+
+  void OpenAsync(const FilePath& path,
+                 int open_flags,
+                 const CompletionCallback& callback);
+  int OpenSync(const FilePath& path, int open_flags);
+
+  void CloseSync();
+
+  void SeekAsync(Whence whence,
+                 int64 offset,
+                 const Int64CompletionCallback& callback);
+  int64 SeekSync(Whence whence, int64 offset);
+
+  void FlushAsync(const CompletionCallback& callback);
+  int FlushSync();
+
+ private:
+  ////////////////////////////////////////////////////////////////////////////
+  // Error code that is platform-dependent but is used in the platform-
+  // independent code implemented in file_stream_context.cc.
+  ////////////////////////////////////////////////////////////////////////////
+  enum {
+#if defined(OS_WIN)
+    ERROR_BAD_FILE = ERROR_INVALID_HANDLE
+#elif defined(OS_POSIX)
+    ERROR_BAD_FILE = EBADF
+#endif
+  };
+
+  ////////////////////////////////////////////////////////////////////////////
+  // Platform-independent methods implemented in file_stream_context.cc.
+  ////////////////////////////////////////////////////////////////////////////
+
+  struct OpenResult {
+    base::PlatformFile file;
+    int error_code;
+  };
+
+  // Map system error into network error code and log it with |bound_net_log_|.
+  int RecordAndMapError(int error, FileErrorSource source) const;
+
+  void BeginOpenEvent(const FilePath& path);
+
+  OpenResult OpenFileImpl(const FilePath& path, int open_flags);
+
+  int ProcessOpenError(int error_code);
+  void OnOpenCompleted(const CompletionCallback& callback, OpenResult result);
+
+  void CloseAndDelete();
+  void OnCloseCompleted();
+
+  Int64CompletionCallback IntToInt64(const CompletionCallback& callback);
+
+  // Checks for IO error that probably happened in async methods.
+  // If there was error reports it.
+  void CheckForIOError(int64* result, FileErrorSource source);
+
+  // Called when asynchronous Seek() is completed.
+  // Reports error if needed and calls callback.
+  void ProcessAsyncResult(const Int64CompletionCallback& callback,
+                          FileErrorSource source,
+                          int64 result);
+
+  // Called when asynchronous Open() or Seek()
+  // is completed. |result| contains the result or a network error code.
+  void OnAsyncCompleted(const Int64CompletionCallback& callback, int64 result);
+
+  ////////////////////////////////////////////////////////////////////////////
+  // Helper stuff which is platform-dependent but is used in the platform-
+  // independent code implemented in file_stream_context.cc. These helpers were
+  // introduced solely to implement as much of the Context methods as
+  // possible independently from platform.
+  ////////////////////////////////////////////////////////////////////////////
+
+#if defined(OS_WIN)
+  int GetLastErrno() { return GetLastError(); }
+  void OnAsyncFileOpened();
+#elif defined(OS_POSIX)
+  int GetLastErrno() { return errno; }
+  void OnAsyncFileOpened() {}
+  void CancelIo(base::PlatformFile) {}
+#endif
+
+  ////////////////////////////////////////////////////////////////////////////
+  // Platform-dependent methods implemented in
+  // file_stream_context_{win,posix}.cc.
+  ////////////////////////////////////////////////////////////////////////////
+
+  // Adjusts the position from where the data is read.
+  int64 SeekFileImpl(Whence whence, int64 offset);
+
+  // Flushes all data written to the stream.
+  int64 FlushFileImpl();
+
+#if defined(OS_WIN)
+  void IOCompletionIsPending(const CompletionCallback& callback, IOBuffer* buf);
+
+  // Implementation of MessageLoopForIO::IOHandler
+  virtual void OnIOCompleted(MessageLoopForIO::IOContext* context,
+                             DWORD bytes_read,
+                             DWORD error) OVERRIDE;
+#elif defined(OS_POSIX)
+  // ReadFileImpl() is a simple wrapper around read() that handles EINTR
+  // signals and calls RecordAndMapError() to map errno to net error codes.
+  int64 ReadFileImpl(scoped_refptr<IOBuffer> buf, int buf_len);
+
+  // WriteFileImpl() is a simple wrapper around write() that handles EINTR
+  // signals and calls MapSystemError() to map errno to net error codes.
+  // It tries to write to completion.
+  int64 WriteFileImpl(scoped_refptr<IOBuffer> buf, int buf_len);
+#endif
+
+  base::PlatformFile file_;
+  bool record_uma_;
+  bool async_in_progress_;
+  bool orphaned_;
+  BoundNetLog bound_net_log_;
+
+#if defined(OS_WIN)
+  MessageLoopForIO::IOContext io_context_;
+  CompletionCallback callback_;
+  scoped_refptr<IOBuffer> in_flight_buf_;
+  FileErrorSource error_source_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(Context);
+};
+
+}  // namespace net
+
+#endif  // NET_BASE_FILE_STREAM_CONTEXT_H_
+
diff --git a/net/base/file_stream_context_posix.cc b/net/base/file_stream_context_posix.cc
new file mode 100644
index 0000000..8316215
--- /dev/null
+++ b/net/base/file_stream_context_posix.cc
@@ -0,0 +1,176 @@
+// 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.
+
+// For 64-bit file access (off_t = off64_t, lseek64, etc).
+#define _FILE_OFFSET_BITS 64
+
+#include "net/base/file_stream_context.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "base/basictypes.h"
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/callback.h"
+#include "base/eintr_wrapper.h"
+#include "base/file_path.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "base/metrics/histogram.h"
+#include "base/task_runner_util.h"
+#include "base/threading/worker_pool.h"
+#include "net/base/io_buffer.h"
+#include "net/base/net_errors.h"
+
+#if defined(OS_ANDROID)
+// Android's bionic libc only supports the LFS transitional API.
+#define off_t off64_t
+#define lseek lseek64
+#define stat stat64
+#define fstat fstat64
+#endif
+
+namespace net {
+
+// We cast back and forth, so make sure it's the size we're expecting.
+COMPILE_ASSERT(sizeof(int64) == sizeof(off_t), off_t_64_bit);
+
+// Make sure our Whence mappings match the system headers.
+COMPILE_ASSERT(FROM_BEGIN   == SEEK_SET &&
+               FROM_CURRENT == SEEK_CUR &&
+               FROM_END     == SEEK_END, whence_matches_system);
+
+FileStream::Context::Context(const BoundNetLog& bound_net_log)
+    : file_(base::kInvalidPlatformFileValue),
+      record_uma_(false),
+      async_in_progress_(false),
+      orphaned_(false),
+      bound_net_log_(bound_net_log) {
+}
+
+FileStream::Context::Context(base::PlatformFile file,
+                             const BoundNetLog& bound_net_log,
+                             int /* open_flags */)
+    : file_(file),
+      record_uma_(false),
+      async_in_progress_(false),
+      orphaned_(false),
+      bound_net_log_(bound_net_log) {
+}
+
+FileStream::Context::~Context() {
+}
+
+int64 FileStream::Context::GetFileSize() const {
+  struct stat info;
+  if (fstat(file_, &info) != 0)
+    return RecordAndMapError(errno, FILE_ERROR_SOURCE_GET_SIZE);
+
+  return static_cast<int64>(info.st_size);
+}
+
+int FileStream::Context::ReadAsync(IOBuffer* in_buf,
+                                   int buf_len,
+                                   const CompletionCallback& callback) {
+  DCHECK(!async_in_progress_);
+
+  scoped_refptr<IOBuffer> buf = in_buf;
+  const bool posted = base::PostTaskAndReplyWithResult(
+      base::WorkerPool::GetTaskRunner(true /* task is slow */),
+      FROM_HERE,
+      base::Bind(&Context::ReadFileImpl,
+                 base::Unretained(this), buf, buf_len),
+      base::Bind(&Context::ProcessAsyncResult,
+                 base::Unretained(this), IntToInt64(callback),
+                 FILE_ERROR_SOURCE_READ));
+  DCHECK(posted);
+
+  async_in_progress_ = true;
+  return ERR_IO_PENDING;
+}
+
+int FileStream::Context::ReadSync(char* in_buf, int buf_len) {
+  scoped_refptr<IOBuffer> buf = new WrappedIOBuffer(in_buf);
+  int64 result = ReadFileImpl(buf, buf_len);
+  CheckForIOError(&result, FILE_ERROR_SOURCE_READ);
+  return result;
+}
+
+int FileStream::Context::WriteAsync(IOBuffer* in_buf,
+                                    int buf_len,
+                                    const CompletionCallback& callback) {
+  DCHECK(!async_in_progress_);
+
+  scoped_refptr<IOBuffer> buf = in_buf;
+  const bool posted = base::PostTaskAndReplyWithResult(
+      base::WorkerPool::GetTaskRunner(true /* task is slow */),
+      FROM_HERE,
+      base::Bind(&Context::WriteFileImpl,
+                 base::Unretained(this), buf, buf_len),
+      base::Bind(&Context::ProcessAsyncResult,
+                 base::Unretained(this), IntToInt64(callback),
+                 FILE_ERROR_SOURCE_WRITE));
+  DCHECK(posted);
+
+  async_in_progress_ = true;
+  return ERR_IO_PENDING;
+}
+
+int FileStream::Context::WriteSync(const char* in_buf, int buf_len) {
+  scoped_refptr<IOBuffer> buf = new WrappedIOBuffer(in_buf);
+  int64 result = WriteFileImpl(buf, buf_len);
+  CheckForIOError(&result, FILE_ERROR_SOURCE_WRITE);
+  return result;
+}
+
+int FileStream::Context::Truncate(int64 bytes) {
+  int result = ftruncate(file_, bytes);
+  if (result == 0)
+    return bytes;
+
+  return RecordAndMapError(errno, FILE_ERROR_SOURCE_SET_EOF);
+}
+
+int64 FileStream::Context::SeekFileImpl(Whence whence, int64 offset) {
+  off_t res = lseek(file_, static_cast<off_t>(offset),
+                    static_cast<int>(whence));
+  if (res == static_cast<off_t>(-1))
+    return errno;
+
+  return res;
+}
+
+int64 FileStream::Context::FlushFileImpl() {
+  ssize_t res = HANDLE_EINTR(fsync(file_));
+  if (res == -1)
+    return errno;
+
+  return res;
+}
+
+int64 FileStream::Context::ReadFileImpl(scoped_refptr<IOBuffer> buf,
+                                        int buf_len) {
+  // Loop in the case of getting interrupted by a signal.
+  ssize_t res = HANDLE_EINTR(read(file_, buf->data(),
+                                  static_cast<size_t>(buf_len)));
+  if (res == -1)
+    return errno;
+
+  return res;
+}
+
+int64 FileStream::Context::WriteFileImpl(scoped_refptr<IOBuffer> buf,
+                                         int buf_len) {
+  ssize_t res = HANDLE_EINTR(write(file_, buf->data(), buf_len));
+  if (res == -1)
+    return errno;
+
+  return res;
+}
+
+}  // namespace net
diff --git a/net/base/file_stream_context_win.cc b/net/base/file_stream_context_win.cc
new file mode 100644
index 0000000..a514ab0
--- /dev/null
+++ b/net/base/file_stream_context_win.cc
@@ -0,0 +1,237 @@
+// 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 "net/base/file_stream_context.h"
+
+#include <windows.h>
+
+#include "base/file_path.h"
+#include "base/logging.h"
+#include "base/metrics/histogram.h"
+#include "base/task_runner_util.h"
+#include "base/threading/worker_pool.h"
+#include "net/base/io_buffer.h"
+#include "net/base/net_errors.h"
+
+namespace net {
+
+// Ensure that we can just use our Whence values directly.
+COMPILE_ASSERT(FROM_BEGIN == FILE_BEGIN, bad_whence_begin);
+COMPILE_ASSERT(FROM_CURRENT == FILE_CURRENT, bad_whence_current);
+COMPILE_ASSERT(FROM_END == FILE_END, bad_whence_end);
+
+namespace {
+
+void SetOffset(OVERLAPPED* overlapped, const LARGE_INTEGER& offset) {
+  overlapped->Offset = offset.LowPart;
+  overlapped->OffsetHigh = offset.HighPart;
+}
+
+void IncrementOffset(OVERLAPPED* overlapped, DWORD count) {
+  LARGE_INTEGER offset;
+  offset.LowPart = overlapped->Offset;
+  offset.HighPart = overlapped->OffsetHigh;
+  offset.QuadPart += static_cast<LONGLONG>(count);
+  SetOffset(overlapped, offset);
+}
+
+}  // namespace
+
+FileStream::Context::Context(const BoundNetLog& bound_net_log)
+    : io_context_(),
+      file_(base::kInvalidPlatformFileValue),
+      record_uma_(false),
+      async_in_progress_(false),
+      orphaned_(false),
+      bound_net_log_(bound_net_log),
+      error_source_(FILE_ERROR_SOURCE_COUNT) {
+  io_context_.handler = this;
+}
+
+FileStream::Context::Context(base::PlatformFile file,
+                             const BoundNetLog& bound_net_log,
+                             int open_flags)
+    : io_context_(),
+      file_(file),
+      record_uma_(false),
+      async_in_progress_(false),
+      orphaned_(false),
+      bound_net_log_(bound_net_log),
+      error_source_(FILE_ERROR_SOURCE_COUNT) {
+  io_context_.handler = this;
+  if (file_ != base::kInvalidPlatformFileValue &&
+      (open_flags & base::PLATFORM_FILE_ASYNC)) {
+    OnAsyncFileOpened();
+  }
+}
+
+FileStream::Context::~Context() {
+}
+
+int64 FileStream::Context::GetFileSize() const {
+  LARGE_INTEGER file_size;
+  if (!GetFileSizeEx(file_, &file_size)) {
+    DWORD error = GetLastError();
+    LOG(WARNING) << "GetFileSizeEx failed: " << error;
+    return RecordAndMapError(error, FILE_ERROR_SOURCE_GET_SIZE);
+  }
+
+  return file_size.QuadPart;
+}
+
+int FileStream::Context::ReadAsync(IOBuffer* buf,
+                                   int buf_len,
+                                   const CompletionCallback& callback) {
+  DCHECK(!async_in_progress_);
+  error_source_ = FILE_ERROR_SOURCE_READ;
+
+  int rv = 0;
+
+  DWORD bytes_read;
+  if (!ReadFile(file_, buf->data(), buf_len,
+                &bytes_read, &io_context_.overlapped)) {
+    DWORD error = GetLastError();
+    if (error == ERROR_IO_PENDING) {
+      IOCompletionIsPending(callback, buf);
+      rv = ERR_IO_PENDING;
+    } else if (error == ERROR_HANDLE_EOF) {
+      rv = 0;  // Report EOF by returning 0 bytes read.
+    } else {
+      LOG(WARNING) << "ReadFile failed: " << error;
+      rv = RecordAndMapError(error, FILE_ERROR_SOURCE_READ);
+    }
+  } else {
+    IOCompletionIsPending(callback, buf);
+    rv = ERR_IO_PENDING;
+  }
+  return rv;
+}
+
+int FileStream::Context::ReadSync(char* buf, int buf_len) {
+  int rv = 0;
+
+  DWORD bytes_read;
+  if (!ReadFile(file_, buf, buf_len, &bytes_read, NULL)) {
+    DWORD error = GetLastError();
+    if (error == ERROR_HANDLE_EOF) {
+      rv = 0;  // Report EOF by returning 0 bytes read.
+    } else {
+      LOG(WARNING) << "ReadFile failed: " << error;
+      rv = RecordAndMapError(error, FILE_ERROR_SOURCE_READ);
+    }
+  } else {
+    rv = static_cast<int>(bytes_read);
+  }
+  return rv;
+}
+
+int FileStream::Context::WriteAsync(IOBuffer* buf,
+                                    int buf_len,
+                                    const CompletionCallback& callback) {
+  error_source_ = FILE_ERROR_SOURCE_WRITE;
+
+  int rv = 0;
+  DWORD bytes_written = 0;
+  if (!WriteFile(file_, buf->data(), buf_len,
+                 &bytes_written, &io_context_.overlapped)) {
+    DWORD error = GetLastError();
+    if (error == ERROR_IO_PENDING) {
+      IOCompletionIsPending(callback, buf);
+      rv = ERR_IO_PENDING;
+    } else {
+      LOG(WARNING) << "WriteFile failed: " << error;
+      rv = RecordAndMapError(error, FILE_ERROR_SOURCE_WRITE);
+    }
+  } else {
+    IOCompletionIsPending(callback, buf);
+    rv = ERR_IO_PENDING;
+  }
+  return rv;
+}
+
+int FileStream::Context::WriteSync(const char* buf, int buf_len) {
+  int rv = 0;
+  DWORD bytes_written = 0;
+  if (!WriteFile(file_, buf, buf_len, &bytes_written, NULL)) {
+    DWORD error = GetLastError();
+    LOG(WARNING) << "WriteFile failed: " << error;
+    rv = RecordAndMapError(error, FILE_ERROR_SOURCE_WRITE);
+  } else {
+    rv = static_cast<int>(bytes_written);
+  }
+  return rv;
+}
+
+int FileStream::Context::Truncate(int64 bytes) {
+  BOOL result = SetEndOfFile(file_);
+  if (result)
+    return bytes;
+
+  DWORD error = GetLastError();
+  LOG(WARNING) << "SetEndOfFile failed: " << error;
+  return RecordAndMapError(error, FILE_ERROR_SOURCE_SET_EOF);
+}
+
+void FileStream::Context::OnAsyncFileOpened() {
+  MessageLoopForIO::current()->RegisterIOHandler(file_, this);
+}
+
+int64 FileStream::Context::SeekFileImpl(Whence whence, int64 offset) {
+  LARGE_INTEGER distance, res;
+  distance.QuadPart = offset;
+  DWORD move_method = static_cast<DWORD>(whence);
+  if (SetFilePointerEx(file_, distance, &res, move_method)) {
+    SetOffset(&io_context_.overlapped, res);
+    return res.QuadPart;
+  }
+
+  return -static_cast<int>(GetLastError());
+}
+
+int64 FileStream::Context::FlushFileImpl() {
+  if (FlushFileBuffers(file_))
+    return OK;
+
+  return -static_cast<int>(GetLastError());
+}
+
+void FileStream::Context::IOCompletionIsPending(
+    const CompletionCallback& callback,
+    IOBuffer* buf) {
+  DCHECK(callback_.is_null());
+  callback_ = callback;
+  in_flight_buf_ = buf;  // Hold until the async operation ends.
+  async_in_progress_ = true;
+}
+
+void FileStream::Context::OnIOCompleted(MessageLoopForIO::IOContext* context,
+                                        DWORD bytes_read,
+                                        DWORD error) {
+  DCHECK_EQ(&io_context_, context);
+  DCHECK(!callback_.is_null());
+  DCHECK(async_in_progress_);
+
+  async_in_progress_ = false;
+  if (orphaned_) {
+    callback_.Reset();
+    in_flight_buf_ = NULL;
+    CloseAndDelete();
+    return;
+  }
+
+  int result = static_cast<int>(bytes_read);
+  if (error && error != ERROR_HANDLE_EOF)
+    result = RecordAndMapError(error, error_source_);
+
+  if (bytes_read)
+    IncrementOffset(&io_context_.overlapped, bytes_read);
+
+  CompletionCallback temp_callback = callback_;
+  callback_.Reset();
+  scoped_refptr<IOBuffer> temp_buf = in_flight_buf_;
+  in_flight_buf_ = NULL;
+  temp_callback.Run(result);
+}
+
+}  // namespace net
diff --git a/net/base/file_stream_posix.cc b/net/base/file_stream_posix.cc
deleted file mode 100644
index 5613fe3..0000000
--- a/net/base/file_stream_posix.cc
+++ /dev/null
@@ -1,683 +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.
-
-// For 64-bit file access (off_t = off64_t, lseek64, etc).
-#define _FILE_OFFSET_BITS 64
-
-#include "net/base/file_stream.h"
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <errno.h>
-
-#include "base/basictypes.h"
-#include "base/bind.h"
-#include "base/bind_helpers.h"
-#include "base/callback.h"
-#include "base/eintr_wrapper.h"
-#include "base/file_path.h"
-#include "base/logging.h"
-#include "base/message_loop.h"
-#include "base/metrics/histogram.h"
-#include "base/string_util.h"
-#include "base/threading/thread_restrictions.h"
-#include "base/threading/worker_pool.h"
-#include "base/synchronization/waitable_event.h"
-#include "net/base/file_stream_metrics.h"
-#include "net/base/file_stream_net_log_parameters.h"
-#include "net/base/io_buffer.h"
-#include "net/base/net_errors.h"
-
-#if defined(OS_ANDROID)
-// Android's bionic libc only supports the LFS transitional API.
-#define off_t off64_t
-#define lseek lseek64
-#define stat stat64
-#define fstat fstat64
-#endif
-
-namespace net {
-
-// We cast back and forth, so make sure it's the size we're expecting.
-COMPILE_ASSERT(sizeof(int64) == sizeof(off_t), off_t_64_bit);
-
-// Make sure our Whence mappings match the system headers.
-COMPILE_ASSERT(FROM_BEGIN   == SEEK_SET &&
-               FROM_CURRENT == SEEK_CUR &&
-               FROM_END     == SEEK_END, whence_matches_system);
-
-namespace {
-
-int RecordAndMapError(int error,
-                      FileErrorSource source,
-                      bool record_uma,
-                      const net::BoundNetLog& bound_net_log) {
-  net::Error net_error = MapSystemError(error);
-
-  bound_net_log.AddEvent(
-      net::NetLog::TYPE_FILE_STREAM_ERROR,
-      base::Bind(&NetLogFileStreamErrorCallback,
-                 source, error, net_error));
-
-  RecordFileError(error, source, record_uma);
-
-  return net_error;
-}
-
-// Opens a file with some network logging.
-// The opened file and the result code are written to |file| and |result|.
-void OpenFile(const FilePath& path,
-              int open_flags,
-              bool record_uma,
-              base::PlatformFile* file,
-              int* result,
-              const net::BoundNetLog& bound_net_log) {
-  std::string file_name = path.AsUTF8Unsafe();
-  bound_net_log.BeginEvent(
-      net::NetLog::TYPE_FILE_STREAM_OPEN,
-      NetLog::StringCallback("file_name", &file_name));
-
-  *result = OK;
-  *file = base::CreatePlatformFile(path, open_flags, NULL, NULL);
-  if (*file == base::kInvalidPlatformFileValue) {
-    bound_net_log.EndEvent(net::NetLog::TYPE_FILE_STREAM_OPEN);
-    *result = RecordAndMapError(errno, FILE_ERROR_SOURCE_OPEN, record_uma,
-                                bound_net_log);
-  }
-}
-
-// Opens a file using OpenFile() and then signals the completion.
-void OpenFileAndSignal(const FilePath& path,
-                       int open_flags,
-                       bool record_uma,
-                       base::PlatformFile* file,
-                       int* result,
-                       base::WaitableEvent* on_io_complete,
-                       const net::BoundNetLog& bound_net_log) {
-  OpenFile(path, open_flags, record_uma, file, result, bound_net_log);
-  on_io_complete->Signal();
-}
-
-// Closes a file with some network logging.
-void CloseFile(base::PlatformFile file,
-               const net::BoundNetLog& bound_net_log) {
-  bound_net_log.AddEvent(net::NetLog::TYPE_FILE_STREAM_CLOSE);
-  if (file == base::kInvalidPlatformFileValue)
-    return;
-
-  if (!base::ClosePlatformFile(file))
-    NOTREACHED();
-  bound_net_log.EndEvent(net::NetLog::TYPE_FILE_STREAM_OPEN);
-}
-
-// Closes a file with CloseFile() and signals the completion.
-void CloseFileAndSignal(base::PlatformFile* file,
-                        base::WaitableEvent* on_io_complete,
-                        const net::BoundNetLog& bound_net_log) {
-  CloseFile(*file, bound_net_log);
-  *file = base::kInvalidPlatformFileValue;
-  on_io_complete->Signal();
-}
-
-// Adjusts the position from where the data is read.
-void SeekFile(base::PlatformFile file,
-              Whence whence,
-              int64 offset,
-              int64* result,
-              bool record_uma,
-              const net::BoundNetLog& bound_net_log) {
-  off_t res = lseek(file, static_cast<off_t>(offset),
-                    static_cast<int>(whence));
-  if (res == static_cast<off_t>(-1)) {
-    *result = RecordAndMapError(errno,
-                                FILE_ERROR_SOURCE_SEEK,
-                                record_uma,
-                                bound_net_log);
-    return;
-  }
-  *result = res;
-}
-
-// Seeks a file by calling SeekSync() and signals the completion.
-void SeekFileAndSignal(base::PlatformFile file,
-                       Whence whence,
-                       int64 offset,
-                       int64* result,
-                       bool record_uma,
-                       base::WaitableEvent* on_io_complete,
-                       const net::BoundNetLog& bound_net_log) {
-  SeekFile(file, whence, offset, result, record_uma, bound_net_log);
-  on_io_complete->Signal();
-}
-
-// ReadFile() is a simple wrapper around read() that handles EINTR signals and
-// calls MapSystemError() to map errno to net error codes.
-void ReadFile(base::PlatformFile file,
-              char* buf,
-              int buf_len,
-              bool record_uma,
-              int* result,
-              const net::BoundNetLog& bound_net_log) {
-  base::ThreadRestrictions::AssertIOAllowed();
-  // read(..., 0) returns 0 to indicate end-of-file.
-
-  // Loop in the case of getting interrupted by a signal.
-  ssize_t res = HANDLE_EINTR(read(file, buf, static_cast<size_t>(buf_len)));
-  if (res == -1) {
-    res = RecordAndMapError(errno, FILE_ERROR_SOURCE_READ,
-                            record_uma, bound_net_log);
-  }
-  *result = res;
-}
-
-// Reads a file using ReadFile() and signals the completion.
-void ReadFileAndSignal(base::PlatformFile file,
-                       scoped_refptr<IOBuffer> buf,
-                       int buf_len,
-                       bool record_uma,
-                       int* result,
-                       base::WaitableEvent* on_io_complete,
-                       const net::BoundNetLog& bound_net_log) {
-  ReadFile(file, buf->data(), buf_len, record_uma, result, bound_net_log);
-  on_io_complete->Signal();
-}
-
-// WriteFile() is a simple wrapper around write() that handles EINTR signals and
-// calls MapSystemError() to map errno to net error codes.  It tries to write to
-// completion.
-void WriteFile(base::PlatformFile file,
-               const char* buf,
-               int buf_len,
-               bool record_uma,
-               int* result,
-               const net::BoundNetLog& bound_net_log) {
-  base::ThreadRestrictions::AssertIOAllowed();
-
-  ssize_t res = HANDLE_EINTR(write(file, buf, buf_len));
-  if (res == -1) {
-    res = RecordAndMapError(errno, FILE_ERROR_SOURCE_WRITE, record_uma,
-                            bound_net_log);
-  }
-  *result = res;
-}
-
-// Writes a file using WriteFile() and signals the completion.
-void WriteFileAndSignal(base::PlatformFile file,
-                        scoped_refptr<IOBuffer> buf,
-                        int buf_len,
-                        bool record_uma,
-                        int* result,
-                        base::WaitableEvent* on_io_complete,
-                        const net::BoundNetLog& bound_net_log) {
-  WriteFile(file, buf->data(), buf_len, record_uma, result, bound_net_log);
-  on_io_complete->Signal();
-}
-
-// FlushFile() is a simple wrapper around fsync() that handles EINTR signals and
-// calls MapSystemError() to map errno to net error codes.  It tries to flush to
-// completion.
-int FlushFile(base::PlatformFile file,
-              bool record_uma,
-              const net::BoundNetLog& bound_net_log) {
-  base::ThreadRestrictions::AssertIOAllowed();
-  ssize_t res = HANDLE_EINTR(fsync(file));
-  if (res == -1) {
-    res = RecordAndMapError(errno, FILE_ERROR_SOURCE_FLUSH, record_uma,
-                            bound_net_log);
-  }
-  return res;
-}
-
-// Flushes a file using FlushFile() and signals the completion.
-void FlushFileAndSignal(base::PlatformFile file,
-                        int* result,
-                        bool record_uma,
-                        base::WaitableEvent* on_io_complete,
-                        const net::BoundNetLog& bound_net_log) {
-  *result = FlushFile(file, record_uma, bound_net_log);
-  on_io_complete->Signal();
-}
-
-// Called when Read(), Write() or Seek() is completed.
-// |result| contains the result or a network error code.
-template <typename R>
-void OnIOComplete(const base::WeakPtr<FileStreamPosix>& stream,
-                  const base::Callback<void(R)>& callback,
-                  R* result) {
-  if (!stream.get())
-    return;
-
-  // Reset this before Run() as Run() may issue a new async operation.
-  stream->ResetOnIOComplete();
-  callback.Run(*result);
-}
-
-}  // namespace
-
-// FileStreamPosix ------------------------------------------------------------
-
-FileStreamPosix::FileStreamPosix(net::NetLog* net_log)
-    : file_(base::kInvalidPlatformFileValue),
-      open_flags_(0),
-      auto_closed_(true),
-      record_uma_(false),
-      bound_net_log_(net::BoundNetLog::Make(net_log,
-                                            net::NetLog::SOURCE_FILESTREAM)),
-      weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
-  bound_net_log_.BeginEvent(net::NetLog::TYPE_FILE_STREAM_ALIVE);
-}
-
-FileStreamPosix::FileStreamPosix(
-    base::PlatformFile file, int flags, net::NetLog* net_log)
-    : file_(file),
-      open_flags_(flags),
-      auto_closed_(false),
-      record_uma_(false),
-      bound_net_log_(net::BoundNetLog::Make(net_log,
-                                            net::NetLog::SOURCE_FILESTREAM)),
-      weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
-  bound_net_log_.BeginEvent(net::NetLog::TYPE_FILE_STREAM_ALIVE);
-}
-
-FileStreamPosix::~FileStreamPosix() {
-  if (open_flags_ & base::PLATFORM_FILE_ASYNC) {
-    // Block until the last open/close/read/write operation is complete.
-    // TODO(satorux): Ideally we should not block. crbug.com/115067
-    WaitForIOCompletion();
-  }
-
-  if (auto_closed_) {
-    if (open_flags_ & base::PLATFORM_FILE_ASYNC) {
-      // Close the file in the background.
-      if (IsOpen()) {
-        const bool posted = base::WorkerPool::PostTask(
-            FROM_HERE,
-            base::Bind(&CloseFile, file_, bound_net_log_),
-            true /* task_is_slow */);
-        DCHECK(posted);
-      }
-    } else {
-      CloseSync();
-    }
-  }
-
-  bound_net_log_.EndEvent(net::NetLog::TYPE_FILE_STREAM_ALIVE);
-}
-
-void FileStreamPosix::Close(const CompletionCallback& callback) {
-  DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
-
-  DCHECK(!weak_ptr_factory_.HasWeakPtrs());
-  DCHECK(!on_io_complete_.get());
-  on_io_complete_.reset(new base::WaitableEvent(
-      false  /* manual_reset */, false  /* initially_signaled */));
-
-  // Passing &file_ to a thread pool looks unsafe but it's safe here as the
-  // destructor ensures that the close operation is complete with
-  // WaitForIOCompletion(). See also the destructor.
-  const bool posted = base::WorkerPool::PostTaskAndReply(
-      FROM_HERE,
-      base::Bind(&CloseFileAndSignal, &file_, on_io_complete_.get(),
-                 bound_net_log_),
-      base::Bind(&FileStreamPosix::OnClosed,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 callback),
-      true /* task_is_slow */);
-
-  DCHECK(posted);
-}
-
-void FileStreamPosix::CloseSync() {
-  // TODO(satorux): Replace the following async stuff with a
-  // DCHECK(open_flags & ASYNC) once once all async clients are migrated to
-  // use Close(). crbug.com/114783
-
-  // Abort any existing asynchronous operations.
-  weak_ptr_factory_.InvalidateWeakPtrs();
-  // Block until the last open/read/write operation is complete.
-  // TODO(satorux): Ideally we should not block. crbug.com/115067
-  WaitForIOCompletion();
-
-  CloseFile(file_, bound_net_log_);
-  file_ = base::kInvalidPlatformFileValue;
-}
-
-int FileStreamPosix::Open(const FilePath& path, int open_flags,
-                     const CompletionCallback& callback) {
-  if (IsOpen()) {
-    DLOG(FATAL) << "File is already open!";
-    return ERR_UNEXPECTED;
-  }
-
-  open_flags_ = open_flags;
-  DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
-
-  DCHECK(!weak_ptr_factory_.HasWeakPtrs());
-  DCHECK(!on_io_complete_.get());
-  on_io_complete_.reset(new base::WaitableEvent(
-      false  /* manual_reset */, false  /* initially_signaled */));
-
-  // Passing &file_ to a thread pool looks unsafe but it's safe here as the
-  // destructor ensures that the open operation is complete with
-  // WaitForIOCompletion(). See also the destructor.
-  int* result = new int(OK);
-  const bool posted = base::WorkerPool::PostTaskAndReply(
-      FROM_HERE,
-      base::Bind(&OpenFileAndSignal,
-                 path, open_flags, record_uma_, &file_, result,
-                 on_io_complete_.get(), bound_net_log_),
-      base::Bind(&OnIOComplete<int>, weak_ptr_factory_.GetWeakPtr(),
-                 callback, base::Owned(result)),
-      true /* task_is_slow */);
-  DCHECK(posted);
-  return ERR_IO_PENDING;
-}
-
-int FileStreamPosix::OpenSync(const FilePath& path, int open_flags) {
-  if (IsOpen()) {
-    DLOG(FATAL) << "File is already open!";
-    return ERR_UNEXPECTED;
-  }
-
-  open_flags_ = open_flags;
-  // TODO(satorux): Put a DCHECK once once all async clients are migrated
-  // to use Open(). crbug.com/114783
-  //
-  // DCHECK(!(open_flags_ & base::PLATFORM_FILE_ASYNC));
-
-  int result = OK;
-  OpenFile(path, open_flags_, record_uma_, &file_, &result, bound_net_log_);
-  return result;
-}
-
-bool FileStreamPosix::IsOpen() const {
-  return file_ != base::kInvalidPlatformFileValue;
-}
-
-int FileStreamPosix::Seek(Whence whence, int64 offset,
-                          const Int64CompletionCallback& callback) {
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  // Make sure we're async and we have no other in-flight async operations.
-  DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
-  DCHECK(!weak_ptr_factory_.HasWeakPtrs());
-  DCHECK(!on_io_complete_.get());
-
-  on_io_complete_.reset(new base::WaitableEvent(
-      false  /* manual_reset */, false  /* initially_signaled */));
-
-  int64* result = new int64(-1);
-  const bool posted = base::WorkerPool::PostTaskAndReply(
-      FROM_HERE,
-      base::Bind(&SeekFileAndSignal, file_, whence, offset, result,
-                 record_uma_, on_io_complete_.get(), bound_net_log_),
-      base::Bind(&OnIOComplete<int64>,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 callback, base::Owned(result)),
-      true /* task is slow */);
-  DCHECK(posted);
-  return ERR_IO_PENDING;
-}
-
-int64 FileStreamPosix::SeekSync(Whence whence, int64 offset) {
-  base::ThreadRestrictions::AssertIOAllowed();
-
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  // If we're in async, make sure we don't have a request in flight.
-  DCHECK(!(open_flags_ & base::PLATFORM_FILE_ASYNC) ||
-         !on_io_complete_.get());
-
-  off_t result = -1;
-  SeekFile(file_, whence, offset, &result, record_uma_, bound_net_log_);
-  return result;
-}
-
-int64 FileStreamPosix::Available() {
-  base::ThreadRestrictions::AssertIOAllowed();
-
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  int64 cur_pos = SeekSync(FROM_CURRENT, 0);
-  if (cur_pos < 0)
-    return cur_pos;
-
-  struct stat info;
-  if (fstat(file_, &info) != 0) {
-    return RecordAndMapError(errno,
-                             FILE_ERROR_SOURCE_GET_SIZE,
-                             record_uma_,
-                             bound_net_log_);
-  }
-
-  int64 size = static_cast<int64>(info.st_size);
-  DCHECK_GT(size, cur_pos);
-
-  return size - cur_pos;
-}
-
-int FileStreamPosix::Read(
-    IOBuffer* in_buf, int buf_len, const CompletionCallback& callback) {
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  // read(..., 0) will return 0, which indicates end-of-file.
-  DCHECK_GT(buf_len, 0);
-  DCHECK(open_flags_ & base::PLATFORM_FILE_READ);
-  DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
-
-  // Make sure we don't have a request in flight.
-  DCHECK(!weak_ptr_factory_.HasWeakPtrs());
-  DCHECK(!on_io_complete_.get());
-
-  on_io_complete_.reset(new base::WaitableEvent(
-      false  /* manual_reset */, false  /* initially_signaled */));
-
-  int* result = new int(OK);
-  scoped_refptr<IOBuffer> buf = in_buf;
-  const bool posted = base::WorkerPool::PostTaskAndReply(
-      FROM_HERE,
-      base::Bind(&ReadFileAndSignal, file_, buf, buf_len,
-                 record_uma_, result, on_io_complete_.get(), bound_net_log_),
-      base::Bind(&OnIOComplete<int>,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 callback, base::Owned(result)),
-      true /* task is slow */);
-  DCHECK(posted);
-  return ERR_IO_PENDING;
-}
-
-int FileStreamPosix::ReadSync(char* buf, int buf_len) {
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  DCHECK(!(open_flags_ & base::PLATFORM_FILE_ASYNC));
-  // read(..., 0) will return 0, which indicates end-of-file.
-  DCHECK_GT(buf_len, 0);
-  DCHECK(open_flags_ & base::PLATFORM_FILE_READ);
-
-  int result = OK;
-  ReadFile(file_, buf, buf_len, record_uma_, &result, bound_net_log_);
-  return result;
-}
-
-int FileStreamPosix::ReadUntilComplete(char *buf, int buf_len) {
-  int to_read = buf_len;
-  int bytes_total = 0;
-
-  do {
-    int bytes_read = ReadSync(buf, to_read);
-    if (bytes_read <= 0) {
-      if (bytes_total == 0)
-        return bytes_read;
-
-      return bytes_total;
-    }
-
-    bytes_total += bytes_read;
-    buf += bytes_read;
-    to_read -= bytes_read;
-  } while (bytes_total < buf_len);
-
-  return bytes_total;
-}
-
-int FileStreamPosix::Write(
-    IOBuffer* in_buf, int buf_len, const CompletionCallback& callback) {
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
-  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
-  // write(..., 0) will return 0, which indicates end-of-file.
-  DCHECK_GT(buf_len, 0);
-
-  // Make sure we don't have a request in flight.
-  DCHECK(!weak_ptr_factory_.HasWeakPtrs());
-  DCHECK(!on_io_complete_.get());
-  on_io_complete_.reset(new base::WaitableEvent(
-      false  /* manual_reset */, false  /* initially_signaled */));
-
-  int* result = new int(OK);
-  scoped_refptr<IOBuffer> buf = in_buf;
-  const bool posted = base::WorkerPool::PostTaskAndReply(
-      FROM_HERE,
-      base::Bind(&WriteFileAndSignal, file_, buf, buf_len,
-                 record_uma_, result, on_io_complete_.get(), bound_net_log_),
-      base::Bind(&OnIOComplete<int>,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 callback, base::Owned(result)),
-      true /* task is slow */);
-  DCHECK(posted);
-  return ERR_IO_PENDING;
-}
-
-int FileStreamPosix::WriteSync(
-    const char* buf, int buf_len) {
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  DCHECK(!(open_flags_ & base::PLATFORM_FILE_ASYNC));
-  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
-  // write(..., 0) will return 0, which indicates end-of-file.
-  DCHECK_GT(buf_len, 0);
-
-  int result = OK;
-  WriteFile(file_, buf, buf_len, record_uma_, &result, bound_net_log_);
-  return result;
-}
-
-int64 FileStreamPosix::Truncate(int64 bytes) {
-  base::ThreadRestrictions::AssertIOAllowed();
-
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  // We'd better be open for writing.
-  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
-
-  // Seek to the position to truncate from.
-  int64 seek_position = SeekSync(FROM_BEGIN, bytes);
-  if (seek_position != bytes)
-    return ERR_UNEXPECTED;
-
-  // And truncate the file.
-  int result = ftruncate(file_, bytes);
-  if (result == 0)
-    return seek_position;
-
-  return RecordAndMapError(errno,
-                           FILE_ERROR_SOURCE_SET_EOF,
-                           record_uma_,
-                           bound_net_log_);
-}
-
-int FileStreamPosix::Flush(const CompletionCallback& callback) {
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  // Make sure we're async and we have no other in-flight async operations.
-  DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
-  DCHECK(!weak_ptr_factory_.HasWeakPtrs());
-  DCHECK(!on_io_complete_.get());
-
-  on_io_complete_.reset(new base::WaitableEvent(
-      false  /* manual_reset */, false  /* initially_signaled */));
-
-  int* result = new int(OK);
-  const bool posted = base::WorkerPool::PostTaskAndReply(
-      FROM_HERE,
-      base::Bind(&FlushFileAndSignal, file_, result,
-                 record_uma_, on_io_complete_.get(), bound_net_log_),
-      base::Bind(&OnIOComplete<int>,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 callback, base::Owned(result)),
-      true /* task is slow */);
-  DCHECK(posted);
-  return ERR_IO_PENDING;
-}
-
-int FileStreamPosix::FlushSync() {
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  return FlushFile(file_, record_uma_, bound_net_log_);
-}
-
-void FileStreamPosix::EnableErrorStatistics() {
-  record_uma_ = true;
-}
-
-void FileStreamPosix::SetBoundNetLogSource(
-    const net::BoundNetLog& owner_bound_net_log) {
-  if ((owner_bound_net_log.source().id == net::NetLog::Source::kInvalidId) &&
-      (bound_net_log_.source().id == net::NetLog::Source::kInvalidId)) {
-    // Both |BoundNetLog|s are invalid.
-    return;
-  }
-
-  // Should never connect to itself.
-  DCHECK_NE(bound_net_log_.source().id, owner_bound_net_log.source().id);
-
-  bound_net_log_.AddEvent(
-      net::NetLog::TYPE_FILE_STREAM_BOUND_TO_OWNER,
-      owner_bound_net_log.source().ToEventParametersCallback());
-
-  owner_bound_net_log.AddEvent(
-      net::NetLog::TYPE_FILE_STREAM_SOURCE,
-      bound_net_log_.source().ToEventParametersCallback());
-}
-
-base::PlatformFile FileStreamPosix::GetPlatformFileForTesting() {
-  return file_;
-}
-
-void FileStreamPosix::ResetOnIOComplete() {
-  on_io_complete_.reset();
-  weak_ptr_factory_.InvalidateWeakPtrs();
-}
-
-void FileStreamPosix::OnClosed(const CompletionCallback& callback) {
-  file_ = base::kInvalidPlatformFileValue;
-
-  // Reset this before Run() as Run() may issue a new async operation.
-  ResetOnIOComplete();
-  callback.Run(OK);
-}
-
-void FileStreamPosix::WaitForIOCompletion() {
-  // http://crbug.com/115067
-  base::ThreadRestrictions::ScopedAllowWait allow_wait;
-  if (on_io_complete_.get()) {
-    on_io_complete_->Wait();
-    on_io_complete_.reset();
-  }
-}
-
-}  // namespace net
diff --git a/net/base/file_stream_posix.h b/net/base/file_stream_posix.h
deleted file mode 100644
index 2ac7d63..0000000
--- a/net/base/file_stream_posix.h
+++ /dev/null
@@ -1,83 +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.
-
-// This file implements FileStream for POSIX.
-
-#ifndef NET_BASE_FILE_STREAM_POSIX_H_
-#define NET_BASE_FILE_STREAM_POSIX_H_
-
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
-#include "base/platform_file.h"
-#include "net/base/completion_callback.h"
-#include "net/base/file_stream_whence.h"
-#include "net/base/net_export.h"
-#include "net/base/net_log.h"
-
-class FilePath;
-
-namespace base {
-class WaitableEvent;
-}
-
-namespace net {
-
-class IOBuffer;
-
-class NET_EXPORT FileStreamPosix {
- public:
-  explicit FileStreamPosix(net::NetLog* net_log);
-  FileStreamPosix(base::PlatformFile file, int flags, net::NetLog* net_log);
-  ~FileStreamPosix();
-
-  // FileStream implementations.
-  void Close(const CompletionCallback& callback);
-  void CloseSync();
-  int Open(const FilePath& path, int open_flags,
-           const CompletionCallback& callback);
-  int OpenSync(const FilePath& path, int open_flags);
-  bool IsOpen() const;
-  int Seek(Whence whence, int64 offset,
-           const Int64CompletionCallback& callback);
-  int64 SeekSync(Whence whence, int64 offset);
-  int64 Available();
-  int Read(IOBuffer* buf, int buf_len, const CompletionCallback& callback);
-  int ReadSync(char* buf, int buf_len);
-  int ReadUntilComplete(char *buf, int buf_len);
-  int Write(IOBuffer* buf, int buf_len, const CompletionCallback& callback);
-  int WriteSync(const char* buf, int buf_len);
-  int64 Truncate(int64 bytes);
-  int Flush(const CompletionCallback& callback);
-  int FlushSync();
-  void EnableErrorStatistics();
-  void SetBoundNetLogSource(
-      const net::BoundNetLog& owner_bound_net_log);
-  base::PlatformFile GetPlatformFileForTesting();
-
-  // Resets on_io_complete_ and WeakPtr's.
-  // Called when Read() or Write() is completed.
-  void ResetOnIOComplete();
-
- private:
-  // Called when the file_ is closed asynchronously.
-  void OnClosed(const CompletionCallback& callback);
-
-  // Waits until the in-flight async open/close/read/write operation is
-  // complete.
-  void WaitForIOCompletion();
-
-  base::PlatformFile file_;
-  int open_flags_;
-  bool auto_closed_;
-  bool record_uma_;
-  net::BoundNetLog bound_net_log_;
-  base::WeakPtrFactory<FileStreamPosix> weak_ptr_factory_;
-  scoped_ptr<base::WaitableEvent> on_io_complete_;
-
-  DISALLOW_COPY_AND_ASSIGN(FileStreamPosix);
-};
-
-}  // namespace net
-
-#endif  // NET_BASE_FILE_STREAM_POSIX_H
diff --git a/net/base/file_stream_unittest.cc b/net/base/file_stream_unittest.cc
index 1042784..f9882c8 100644
--- a/net/base/file_stream_unittest.cc
+++ b/net/base/file_stream_unittest.cc
@@ -33,46 +33,6 @@ IOBufferWithSize* CreateTestDataBuffer() {
   return buf;
 }
 
-// This NetLog is used for notifying when a file stream is closed
-// (i.e. TYPE_FILE_STREAM_CLOSE event is recorded).
-class NetLogForNotifyingFileClosure : public NetLog {
- public:
-  NetLogForNotifyingFileClosure()
-      : last_id_(0),
-        on_closure_(false /* manual_reset */, false /* initially_signaled */) {
-  }
-
-  // Wait until a file closure event is recorded.
-  bool WaitForClosure() {
-    const base::TimeDelta timeout(TestTimeouts::action_max_timeout());
-    return on_closure_.TimedWait(timeout);
-  }
-
-  // NetLog overrides:
-  virtual void OnAddEntry(const net::NetLog::Entry& entry) OVERRIDE {
-    if (entry.type() == TYPE_FILE_STREAM_CLOSE)
-      on_closure_.Signal();
-  }
-
-  virtual uint32 NextID() OVERRIDE { return ++last_id_; }
-  virtual LogLevel GetLogLevel() const OVERRIDE { return LOG_ALL; }
-  virtual void AddThreadSafeObserver(ThreadSafeObserver* observer,
-                                     LogLevel log_level) OVERRIDE {
-    NOTIMPLEMENTED();
-  }
-  virtual void SetObserverLogLevel(ThreadSafeObserver* observer,
-                                   LogLevel log_level) OVERRIDE {
-    NOTIMPLEMENTED();
-  }
-  virtual void RemoveThreadSafeObserver(ThreadSafeObserver* observer) OVERRIDE {
-    NOTIMPLEMENTED();
-  }
-
- private:
-  uint32 last_id_;
-  base::WaitableEvent on_closure_;
-};
-
 }  // namespace
 
 class FileStreamTest : public PlatformTest {
@@ -113,7 +73,7 @@ TEST_F(FileStreamTest, BasicOpenClose) {
   EXPECT_FALSE(base::GetPlatformFileInfo(file, &info));
 }
 
-TEST_F(FileStreamTest, FileHandleLeftOpen) {
+TEST_F(FileStreamTest, FileHandleNotLeftOpen) {
   bool created = false;
   ASSERT_EQ(kTestDataSize,
       file_util::WriteFile(temp_file_path(), kTestData, kTestDataSize));
@@ -129,10 +89,9 @@ TEST_F(FileStreamTest, FileHandleLeftOpen) {
 
   EXPECT_NE(base::kInvalidPlatformFileValue, file);
   base::PlatformFileInfo info;
-  // The file should still be open.
-  EXPECT_TRUE(base::GetPlatformFileInfo(file, &info));
-  // Clean up.
-  EXPECT_TRUE(base::ClosePlatformFile(file));
+  // The file should be closed.
+  EXPECT_FALSE(base::GetPlatformFileInfo(file, &info));
+  EXPECT_FALSE(base::ClosePlatformFile(file));
 }
 
 // Test the use of FileStream with a file handle provided at construction.
@@ -147,26 +106,26 @@ TEST_F(FileStreamTest, UseFileHandle) {
       temp_file_path(), flags, &created, NULL);
 
   // Seek to the beginning of the file and read.
-  FileStream read_stream(file, flags, NULL);
-  ASSERT_EQ(0, read_stream.SeekSync(FROM_BEGIN, 0));
-  ASSERT_EQ(kTestDataSize, read_stream.Available());
+  scoped_ptr<FileStream> read_stream(new FileStream(file, flags, NULL));
+  ASSERT_EQ(0, read_stream->SeekSync(FROM_BEGIN, 0));
+  ASSERT_EQ(kTestDataSize, read_stream->Available());
   // Read into buffer and compare.
   char buffer[kTestDataSize];
   ASSERT_EQ(kTestDataSize,
-            read_stream.ReadSync(buffer, kTestDataSize));
+            read_stream->ReadSync(buffer, kTestDataSize));
   ASSERT_EQ(0, memcmp(kTestData, buffer, kTestDataSize));
-  read_stream.CloseSync();
+  read_stream.reset();
 
   // 2. Test writing with a file handle.
   file_util::Delete(temp_file_path(), false);
   flags = base::PLATFORM_FILE_OPEN_ALWAYS | base::PLATFORM_FILE_WRITE;
   file = base::CreatePlatformFile(temp_file_path(), flags, &created, NULL);
 
-  FileStream write_stream(file, flags, NULL);
-  ASSERT_EQ(0, write_stream.SeekSync(FROM_BEGIN, 0));
+  scoped_ptr<FileStream> write_stream(new FileStream(file, flags, NULL));
+  ASSERT_EQ(0, write_stream->SeekSync(FROM_BEGIN, 0));
   ASSERT_EQ(kTestDataSize,
-            write_stream.WriteSync(kTestData, kTestDataSize));
-  write_stream.CloseSync();
+            write_stream->WriteSync(kTestData, kTestDataSize));
+  write_stream.reset();
 
   // Read into buffer and compare to make sure the handle worked fine.
   ASSERT_EQ(kTestDataSize,
@@ -258,38 +217,6 @@ TEST_F(FileStreamTest, AsyncRead) {
   EXPECT_EQ(kTestData, data_read);
 }
 
-TEST_F(FileStreamTest, AsyncRead_EarlyClose) {
-  int64 file_size;
-  bool ok = file_util::GetFileSize(temp_file_path(), &file_size);
-  EXPECT_TRUE(ok);
-
-  FileStream stream(NULL);
-  int flags = base::PLATFORM_FILE_OPEN |
-              base::PLATFORM_FILE_READ |
-              base::PLATFORM_FILE_ASYNC;
-  int rv = stream.OpenSync(temp_file_path(), flags);
-  EXPECT_EQ(OK, rv);
-
-  int64 total_bytes_avail = stream.Available();
-  EXPECT_EQ(file_size, total_bytes_avail);
-
-  TestCompletionCallback callback;
-
-  scoped_refptr<IOBufferWithSize> buf = new IOBufferWithSize(4);
-  rv = stream.Read(buf, buf->size(), callback.callback());
-  stream.CloseSync();
-  if (rv < 0) {
-    EXPECT_EQ(ERR_IO_PENDING, rv);
-    // The callback should not be called if the request is cancelled.
-    MessageLoop::current()->RunAllPending();
-    EXPECT_FALSE(callback.have_result());
-  } else {
-    EXPECT_EQ(std::string(kTestData, rv), std::string(buf->data(), rv));
-  }
-}
-
-// Similar to AsyncRead_EarlyClose but deletes a stream instead, to ensure
-// that deleting a stream is safe while an async read is in flight.
 TEST_F(FileStreamTest, AsyncRead_EarlyDelete) {
   int64 file_size;
   bool ok = file_util::GetFileSize(temp_file_path(), &file_size);
@@ -320,47 +247,6 @@ TEST_F(FileStreamTest, AsyncRead_EarlyDelete) {
   }
 }
 
-// Similar to AsyncRead_EarlyDelete but using a given file handler rather than
-// calling FileStream::Open, to ensure that deleting a stream with in-flight
-// operation without auto-closing feature is also ok.
-TEST_F(FileStreamTest, AsyncRead_EarlyDelete_NoAutoClose) {
-  int64 file_size;
-  bool ok = file_util::GetFileSize(temp_file_path(), &file_size);
-  EXPECT_TRUE(ok);
-
-  bool created = false;
-  int flags = base::PLATFORM_FILE_OPEN |
-              base::PLATFORM_FILE_READ |
-              base::PLATFORM_FILE_ASYNC;
-  base::PlatformFileError error_code = base::PLATFORM_FILE_ERROR_FAILED;
-  base::PlatformFile file = base::CreatePlatformFile(
-      temp_file_path(), flags, &created, &error_code);
-  EXPECT_EQ(base::PLATFORM_FILE_OK, error_code);
-
-  scoped_ptr<FileStream> stream(new FileStream(file, flags, NULL));
-  int64 total_bytes_avail = stream->Available();
-  EXPECT_EQ(file_size, total_bytes_avail);
-
-  TestCompletionCallback callback;
-  scoped_refptr<IOBufferWithSize> buf = new IOBufferWithSize(4);
-  int rv = stream->Read(buf, buf->size(), callback.callback());
-  stream.reset();  // Delete instead of closing it.
-  if (rv < 0) {
-    EXPECT_EQ(ERR_IO_PENDING, rv);
-    // The callback should not be called if the request is cancelled.
-    MessageLoop::current()->RunAllPending();
-    EXPECT_FALSE(callback.have_result());
-  } else {
-    EXPECT_EQ(std::string(kTestData, rv), std::string(buf->data(), rv));
-  }
-
-  base::PlatformFileInfo info;
-  // The file should still be open.
-  EXPECT_TRUE(base::GetPlatformFileInfo(file, &info));
-  // Clean up.
-  EXPECT_TRUE(base::ClosePlatformFile(file));
-}
-
 TEST_F(FileStreamTest, BasicRead_FromOffset) {
   int64 file_size;
   bool ok = file_util::GetFileSize(temp_file_path(), &file_size);
@@ -496,10 +382,10 @@ TEST_F(FileStreamTest, AsyncSeekAround) {
 }
 
 TEST_F(FileStreamTest, BasicWrite) {
-  FileStream stream(NULL);
+  scoped_ptr<FileStream> stream(new FileStream(NULL));
   int flags = base::PLATFORM_FILE_CREATE_ALWAYS |
               base::PLATFORM_FILE_WRITE;
-  int rv = stream.OpenSync(temp_file_path(), flags);
+  int rv = stream->OpenSync(temp_file_path(), flags);
   EXPECT_EQ(OK, rv);
 
   int64 file_size;
@@ -507,9 +393,9 @@ TEST_F(FileStreamTest, BasicWrite) {
   EXPECT_TRUE(ok);
   EXPECT_EQ(0, file_size);
 
-  rv = stream.WriteSync(kTestData, kTestDataSize);
+  rv = stream->WriteSync(kTestData, kTestDataSize);
   EXPECT_EQ(kTestDataSize, rv);
-  stream.CloseSync();
+  stream.reset();
 
   ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
@@ -551,12 +437,12 @@ TEST_F(FileStreamTest, AsyncWrite) {
   EXPECT_EQ(file_size, total_bytes_written);
 }
 
-TEST_F(FileStreamTest, AsyncWrite_EarlyClose) {
-  FileStream stream(NULL);
+TEST_F(FileStreamTest, AsyncWrite_EarlyDelete) {
+  scoped_ptr<FileStream> stream(new FileStream(NULL));
   int flags = base::PLATFORM_FILE_CREATE_ALWAYS |
               base::PLATFORM_FILE_WRITE |
               base::PLATFORM_FILE_ASYNC;
-  int rv = stream.OpenSync(temp_file_path(), flags);
+  int rv = stream->OpenSync(temp_file_path(), flags);
   EXPECT_EQ(OK, rv);
 
   int64 file_size;
@@ -567,8 +453,8 @@ TEST_F(FileStreamTest, AsyncWrite_EarlyClose) {
   TestCompletionCallback callback;
 
   scoped_refptr<IOBufferWithSize> buf = CreateTestDataBuffer();
-  rv = stream.Write(buf, buf->size(), callback.callback());
-  stream.CloseSync();
+  rv = stream->Write(buf, buf->size(), callback.callback());
+  stream.reset();
   if (rv < 0) {
     EXPECT_EQ(ERR_IO_PENDING, rv);
     // The callback should not be called if the request is cancelled.
@@ -582,10 +468,10 @@ TEST_F(FileStreamTest, AsyncWrite_EarlyClose) {
 }
 
 TEST_F(FileStreamTest, BasicWrite_FromOffset) {
-  FileStream stream(NULL);
+  scoped_ptr<FileStream> stream(new FileStream(NULL));
   int flags = base::PLATFORM_FILE_OPEN |
               base::PLATFORM_FILE_WRITE;
-  int rv = stream.OpenSync(temp_file_path(), flags);
+  int rv = stream->OpenSync(temp_file_path(), flags);
   EXPECT_EQ(OK, rv);
 
   int64 file_size;
@@ -594,12 +480,12 @@ TEST_F(FileStreamTest, BasicWrite_FromOffset) {
   EXPECT_EQ(kTestDataSize, file_size);
 
   const int64 kOffset = 0;
-  int64 new_offset = stream.SeekSync(FROM_END, kOffset);
+  int64 new_offset = stream->SeekSync(FROM_END, kOffset);
   EXPECT_EQ(kTestDataSize, new_offset);
 
-  rv = stream.WriteSync(kTestData, kTestDataSize);
+  rv = stream->WriteSync(kTestData, kTestDataSize);
   EXPECT_EQ(kTestDataSize, rv);
-  stream.CloseSync();
+  stream.reset();
 
   ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
@@ -652,14 +538,14 @@ TEST_F(FileStreamTest, BasicReadWrite) {
   bool ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
 
-  FileStream stream(NULL);
+  scoped_ptr<FileStream> stream(new FileStream(NULL));
   int flags = base::PLATFORM_FILE_OPEN |
               base::PLATFORM_FILE_READ |
               base::PLATFORM_FILE_WRITE;
-  int rv = stream.OpenSync(temp_file_path(), flags);
+  int rv = stream->OpenSync(temp_file_path(), flags);
   EXPECT_EQ(OK, rv);
 
-  int64 total_bytes_avail = stream.Available();
+  int64 total_bytes_avail = stream->Available();
   EXPECT_EQ(file_size, total_bytes_avail);
 
   int total_bytes_read = 0;
@@ -667,7 +553,7 @@ TEST_F(FileStreamTest, BasicReadWrite) {
   std::string data_read;
   for (;;) {
     char buf[4];
-    rv = stream.ReadSync(buf, arraysize(buf));
+    rv = stream->ReadSync(buf, arraysize(buf));
     EXPECT_LE(0, rv);
     if (rv <= 0)
       break;
@@ -677,9 +563,9 @@ TEST_F(FileStreamTest, BasicReadWrite) {
   EXPECT_EQ(file_size, total_bytes_read);
   EXPECT_TRUE(data_read == kTestData);
 
-  rv = stream.WriteSync(kTestData, kTestDataSize);
+  rv = stream->WriteSync(kTestData, kTestDataSize);
   EXPECT_EQ(kTestDataSize, rv);
-  stream.CloseSync();
+  stream.reset();
 
   ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
@@ -691,23 +577,23 @@ TEST_F(FileStreamTest, BasicWriteRead) {
   bool ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
 
-  FileStream stream(NULL);
+  scoped_ptr<FileStream> stream(new FileStream(NULL));
   int flags = base::PLATFORM_FILE_OPEN |
               base::PLATFORM_FILE_READ |
               base::PLATFORM_FILE_WRITE;
-  int rv = stream.OpenSync(temp_file_path(), flags);
+  int rv = stream->OpenSync(temp_file_path(), flags);
   EXPECT_EQ(OK, rv);
 
-  int64 total_bytes_avail = stream.Available();
+  int64 total_bytes_avail = stream->Available();
   EXPECT_EQ(file_size, total_bytes_avail);
 
-  int64 offset = stream.SeekSync(FROM_END, 0);
+  int64 offset = stream->SeekSync(FROM_END, 0);
   EXPECT_EQ(offset, file_size);
 
-  rv = stream.WriteSync(kTestData, kTestDataSize);
+  rv = stream->WriteSync(kTestData, kTestDataSize);
   EXPECT_EQ(kTestDataSize, rv);
 
-  offset = stream.SeekSync(FROM_BEGIN, 0);
+  offset = stream->SeekSync(FROM_BEGIN, 0);
   EXPECT_EQ(0, offset);
 
   int64 total_bytes_read = 0;
@@ -715,14 +601,14 @@ TEST_F(FileStreamTest, BasicWriteRead) {
   std::string data_read;
   for (;;) {
     char buf[4];
-    rv = stream.ReadSync(buf, arraysize(buf));
+    rv = stream->ReadSync(buf, arraysize(buf));
     EXPECT_LE(0, rv);
     if (rv <= 0)
       break;
     total_bytes_read += rv;
     data_read.append(buf, rv);
   }
-  stream.CloseSync();
+  stream.reset();
 
   ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
@@ -739,15 +625,15 @@ TEST_F(FileStreamTest, BasicAsyncReadWrite) {
   bool ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
 
-  FileStream stream(NULL);
+  scoped_ptr<FileStream> stream(new FileStream(NULL));
   int flags = base::PLATFORM_FILE_OPEN |
               base::PLATFORM_FILE_READ |
               base::PLATFORM_FILE_WRITE |
               base::PLATFORM_FILE_ASYNC;
-  int rv = stream.OpenSync(temp_file_path(), flags);
+  int rv = stream->OpenSync(temp_file_path(), flags);
   EXPECT_EQ(OK, rv);
 
-  int64 total_bytes_avail = stream.Available();
+  int64 total_bytes_avail = stream->Available();
   EXPECT_EQ(file_size, total_bytes_avail);
 
   TestCompletionCallback callback;
@@ -756,7 +642,7 @@ TEST_F(FileStreamTest, BasicAsyncReadWrite) {
   std::string data_read;
   for (;;) {
     scoped_refptr<IOBufferWithSize> buf = new IOBufferWithSize(4);
-    rv = stream.Read(buf, buf->size(), callback.callback());
+    rv = stream->Read(buf, buf->size(), callback.callback());
     if (rv == ERR_IO_PENDING)
       rv = callback.WaitForResult();
     EXPECT_LE(0, rv);
@@ -774,8 +660,8 @@ TEST_F(FileStreamTest, BasicAsyncReadWrite) {
   scoped_refptr<DrainableIOBuffer> drainable =
       new DrainableIOBuffer(buf, buf->size());
   while (total_bytes_written != kTestDataSize) {
-    rv = stream.Write(drainable, drainable->BytesRemaining(),
-                      callback.callback());
+    rv = stream->Write(drainable, drainable->BytesRemaining(),
+                       callback.callback());
     if (rv == ERR_IO_PENDING)
       rv = callback.WaitForResult();
     EXPECT_LT(0, rv);
@@ -785,7 +671,7 @@ TEST_F(FileStreamTest, BasicAsyncReadWrite) {
     total_bytes_written += rv;
   }
 
-  stream.CloseSync();
+  stream.reset();
 
   ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
@@ -797,19 +683,19 @@ TEST_F(FileStreamTest, BasicAsyncWriteRead) {
   bool ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
 
-  FileStream stream(NULL);
+  scoped_ptr<FileStream> stream(new FileStream(NULL));
   int flags = base::PLATFORM_FILE_OPEN |
               base::PLATFORM_FILE_READ |
               base::PLATFORM_FILE_WRITE |
               base::PLATFORM_FILE_ASYNC;
-  int rv = stream.OpenSync(temp_file_path(), flags);
+  int rv = stream->OpenSync(temp_file_path(), flags);
   EXPECT_EQ(OK, rv);
 
-  int64 total_bytes_avail = stream.Available();
+  int64 total_bytes_avail = stream->Available();
   EXPECT_EQ(file_size, total_bytes_avail);
 
   TestInt64CompletionCallback callback64;
-  rv = stream.Seek(FROM_END, 0, callback64.callback());
+  rv = stream->Seek(FROM_END, 0, callback64.callback());
   ASSERT_EQ(ERR_IO_PENDING, rv);
   int64 offset = callback64.WaitForResult();
   EXPECT_EQ(offset, file_size);
@@ -821,7 +707,7 @@ TEST_F(FileStreamTest, BasicAsyncWriteRead) {
   scoped_refptr<DrainableIOBuffer> drainable =
       new DrainableIOBuffer(buf, buf->size());
   while (total_bytes_written != kTestDataSize) {
-    rv = stream.Write(drainable, drainable->BytesRemaining(),
+    rv = stream->Write(drainable, drainable->BytesRemaining(),
                       callback.callback());
     if (rv == ERR_IO_PENDING)
       rv = callback.WaitForResult();
@@ -834,7 +720,7 @@ TEST_F(FileStreamTest, BasicAsyncWriteRead) {
 
   EXPECT_EQ(kTestDataSize, total_bytes_written);
 
-  rv = stream.Seek(FROM_BEGIN, 0, callback64.callback());
+  rv = stream->Seek(FROM_BEGIN, 0, callback64.callback());
   ASSERT_EQ(ERR_IO_PENDING, rv);
   offset = callback64.WaitForResult();
   EXPECT_EQ(0, offset);
@@ -844,7 +730,7 @@ TEST_F(FileStreamTest, BasicAsyncWriteRead) {
   std::string data_read;
   for (;;) {
     scoped_refptr<IOBufferWithSize> buf = new IOBufferWithSize(4);
-    rv = stream.Read(buf, buf->size(), callback.callback());
+    rv = stream->Read(buf, buf->size(), callback.callback());
     if (rv == ERR_IO_PENDING)
       rv = callback.WaitForResult();
     EXPECT_LE(0, rv);
@@ -853,7 +739,7 @@ TEST_F(FileStreamTest, BasicAsyncWriteRead) {
     total_bytes_read += rv;
     data_read.append(buf->data(), rv);
   }
-  stream.CloseSync();
+  stream.reset();
 
   ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
@@ -963,34 +849,34 @@ TEST_F(FileStreamTest, AsyncWriteRead) {
   bool ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
 
-  FileStream stream(NULL);
+  scoped_ptr<FileStream> stream(new FileStream(NULL));
   int flags = base::PLATFORM_FILE_OPEN |
               base::PLATFORM_FILE_READ |
               base::PLATFORM_FILE_WRITE |
               base::PLATFORM_FILE_ASYNC;
-  int rv = stream.OpenSync(temp_file_path(), flags);
+  int rv = stream->OpenSync(temp_file_path(), flags);
   EXPECT_EQ(OK, rv);
 
-  int64 total_bytes_avail = stream.Available();
+  int64 total_bytes_avail = stream->Available();
   EXPECT_EQ(file_size, total_bytes_avail);
 
-  int64 offset = stream.SeekSync(FROM_END, 0);
+  int64 offset = stream->SeekSync(FROM_END, 0);
   EXPECT_EQ(offset, file_size);
 
   int total_bytes_written = 0;
   int total_bytes_read = 0;
   std::string data_read;
-  TestWriteReadCompletionCallback callback(&stream, &total_bytes_written,
+  TestWriteReadCompletionCallback callback(stream.get(), &total_bytes_written,
                                            &total_bytes_read, &data_read);
 
   scoped_refptr<IOBufferWithSize> buf = CreateTestDataBuffer();
-  rv = stream.Write(buf, buf->size(), callback.callback());
+  rv = stream->Write(buf, buf->size(), callback.callback());
   if (rv == ERR_IO_PENDING)
     rv = callback.WaitForResult();
   EXPECT_LT(0, rv);
   EXPECT_EQ(kTestDataSize, total_bytes_written);
 
-  stream.CloseSync();
+  stream.reset();
 
   ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
@@ -1046,8 +932,6 @@ class TestWriteCloseCompletionCallback {
       rv = callback.WaitForResult();
       drainable_->DidConsume(total_bytes_written);
       *total_bytes_written_ += total_bytes_written;
-    } else {  // We're done writing all data.  Close the file.
-      stream_->CloseSync();
     }
 
     result_ = *total_bytes_written_;
@@ -1073,30 +957,32 @@ TEST_F(FileStreamTest, AsyncWriteClose) {
   bool ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
 
-  FileStream stream(NULL);
+  scoped_ptr<FileStream> stream(new FileStream(NULL));
   int flags = base::PLATFORM_FILE_OPEN |
               base::PLATFORM_FILE_READ |
               base::PLATFORM_FILE_WRITE |
               base::PLATFORM_FILE_ASYNC;
-  int rv = stream.OpenSync(temp_file_path(), flags);
+  int rv = stream->OpenSync(temp_file_path(), flags);
   EXPECT_EQ(OK, rv);
 
-  int64 total_bytes_avail = stream.Available();
+  int64 total_bytes_avail = stream->Available();
   EXPECT_EQ(file_size, total_bytes_avail);
 
-  int64 offset = stream.SeekSync(FROM_END, 0);
+  int64 offset = stream->SeekSync(FROM_END, 0);
   EXPECT_EQ(offset, file_size);
 
   int total_bytes_written = 0;
-  TestWriteCloseCompletionCallback callback(&stream, &total_bytes_written);
+  TestWriteCloseCompletionCallback callback(stream.get(), &total_bytes_written);
 
   scoped_refptr<IOBufferWithSize> buf = CreateTestDataBuffer();
-  rv = stream.Write(buf, buf->size(), callback.callback());
+  rv = stream->Write(buf, buf->size(), callback.callback());
   if (rv == ERR_IO_PENDING)
     total_bytes_written = callback.WaitForResult();
   EXPECT_LT(0, total_bytes_written);
   EXPECT_EQ(kTestDataSize, total_bytes_written);
 
+  stream.reset();
+
   ok = file_util::GetFileSize(temp_file_path(), &file_size);
   EXPECT_TRUE(ok);
   EXPECT_EQ(kTestDataSize * 2, file_size);
@@ -1106,21 +992,21 @@ TEST_F(FileStreamTest, AsyncWriteClose) {
 TEST_F(FileStreamTest, Truncate) {
   int flags = base::PLATFORM_FILE_CREATE_ALWAYS | base::PLATFORM_FILE_WRITE;
 
-  FileStream write_stream(NULL);
-  ASSERT_EQ(OK, write_stream.OpenSync(temp_file_path(), flags));
+  scoped_ptr<FileStream> write_stream(new FileStream(NULL));
+  ASSERT_EQ(OK, write_stream->OpenSync(temp_file_path(), flags));
 
   // Write some data to the file.
   const char test_data[] = "0123456789";
-  write_stream.WriteSync(test_data, arraysize(test_data));
+  write_stream->WriteSync(test_data, arraysize(test_data));
 
   // Truncate the file.
-  ASSERT_EQ(4, write_stream.Truncate(4));
+  ASSERT_EQ(4, write_stream->Truncate(4));
 
   // Write again.
-  write_stream.WriteSync(test_data, 4);
+  write_stream->WriteSync(test_data, 4);
 
   // Close the stream.
-  write_stream.CloseSync();
+  write_stream.reset();
 
   // Read in the contents and make sure we get back what we expected.
   std::string read_contents;
@@ -1129,97 +1015,6 @@ TEST_F(FileStreamTest, Truncate) {
   EXPECT_EQ("01230123", read_contents);
 }
 
-TEST_F(FileStreamTest, AsyncBasicOpenClose) {
-  FileStream stream(NULL);
-  int flags = base::PLATFORM_FILE_OPEN |
-              base::PLATFORM_FILE_READ |
-              base::PLATFORM_FILE_ASYNC;
-  TestCompletionCallback callback;
-  int rv = stream.Open(temp_file_path(), flags, callback.callback());
-  EXPECT_EQ(ERR_IO_PENDING, rv);
-  EXPECT_EQ(OK, callback.WaitForResult());
-  EXPECT_TRUE(stream.IsOpen());
-
-  stream.Close(callback.callback());
-  EXPECT_EQ(OK, callback.WaitForResult());
-  EXPECT_FALSE(stream.IsOpen());
-}
-
-TEST_F(FileStreamTest, SyncCloseTwice) {
-  FileStream stream(NULL);
-  int flags = base::PLATFORM_FILE_OPEN |
-              base::PLATFORM_FILE_READ;
-  int rv = stream.OpenSync(temp_file_path(), flags);
-  EXPECT_EQ(OK, rv);
-  EXPECT_TRUE(stream.IsOpen());
-
-  // Closing twice should be safe.
-  stream.CloseSync();
-  EXPECT_FALSE(stream.IsOpen());
-
-  stream.CloseSync();
-  EXPECT_FALSE(stream.IsOpen());
-}
-
-TEST_F(FileStreamTest, AsyncCloseTwice) {
-  FileStream stream(NULL);
-  int flags = base::PLATFORM_FILE_OPEN |
-      base::PLATFORM_FILE_READ |
-      base::PLATFORM_FILE_ASYNC;
-  TestCompletionCallback callback;
-  int rv = stream.Open(temp_file_path(), flags, callback.callback());
-  EXPECT_EQ(ERR_IO_PENDING, rv);
-  EXPECT_EQ(OK, callback.WaitForResult());
-  EXPECT_TRUE(stream.IsOpen());
-
-  // Closing twice should be safe.
-  stream.Close(callback.callback());
-  EXPECT_EQ(OK, callback.WaitForResult());
-  EXPECT_FALSE(stream.IsOpen());
-
-  stream.Close(callback.callback());
-  EXPECT_EQ(OK, callback.WaitForResult());
-  EXPECT_FALSE(stream.IsOpen());
-}
-
-// TODO(satorux): This should be gone once all once all async clients are
-// migrated to use Close(). crbug.com/114783
-TEST_F(FileStreamTest, AsyncWriteAndCloseSync) {
-  FileStream stream(NULL);
-  int flags = base::PLATFORM_FILE_OPEN |
-      base::PLATFORM_FILE_WRITE |
-      base::PLATFORM_FILE_ASYNC;
-  TestCompletionCallback callback;
-  int rv = stream.Open(temp_file_path(), flags, callback.callback());
-  EXPECT_EQ(ERR_IO_PENDING, rv);
-  EXPECT_EQ(OK, callback.WaitForResult());
-  EXPECT_TRUE(stream.IsOpen());
-
-  // Write some data asynchronously.
-  scoped_refptr<IOBufferWithSize> buf = CreateTestDataBuffer();
-  stream.Write(buf, buf->size(), callback.callback());
-
-  // Close the stream without waiting for the completion.
-  stream.CloseSync();
-}
-
-// TODO(satorux): This should be gone once all once all async clients are
-// migrated to use Close(). crbug.com/114783
-TEST_F(FileStreamTest, AsyncOpenAndCloseSync) {
-  FileStream stream(NULL);
-  int flags = base::PLATFORM_FILE_OPEN |
-      base::PLATFORM_FILE_WRITE |
-      base::PLATFORM_FILE_ASYNC;
-  TestCompletionCallback open_callback;
-  int rv = stream.Open(temp_file_path(), flags, open_callback.callback());
-  EXPECT_EQ(ERR_IO_PENDING, rv);
-
-  // Close the stream without waiting for the completion. Should be safe.
-  stream.CloseSync();
-  // open_callback won't be called.
-  EXPECT_FALSE(open_callback.have_result());
-}
-
 TEST_F(FileStreamTest, AsyncOpenAndDelete) {
   scoped_ptr<FileStream> stream(new FileStream(NULL));
   int flags = base::PLATFORM_FILE_OPEN |
@@ -1233,30 +1028,10 @@ TEST_F(FileStreamTest, AsyncOpenAndDelete) {
   // complete. Should be safe.
   stream.reset();
   // open_callback won't be called.
+  MessageLoop::current()->RunUntilIdle();
   EXPECT_FALSE(open_callback.have_result());
 }
 
-TEST_F(FileStreamTest, AsyncCloseAndDelete) {
-  scoped_ptr<FileStream> stream(new FileStream(NULL));
-  int flags = base::PLATFORM_FILE_OPEN |
-      base::PLATFORM_FILE_WRITE |
-      base::PLATFORM_FILE_ASYNC;
-  TestCompletionCallback open_callback;
-  int rv = stream->Open(temp_file_path(), flags, open_callback.callback());
-  EXPECT_EQ(ERR_IO_PENDING, rv);
-  EXPECT_EQ(OK, open_callback.WaitForResult());
-  EXPECT_TRUE(stream->IsOpen());
-
-  TestCompletionCallback close_callback;
-  stream->Close(close_callback.callback());
-
-  // Delete the stream without waiting for the close operation to be
-  // complete. Should be safe.
-  stream.reset();
-  // close_callback won't be called.
-  EXPECT_FALSE(close_callback.have_result());
-}
-
 }  // namespace
 
 }  // namespace net
diff --git a/net/base/file_stream_win.cc b/net/base/file_stream_win.cc
deleted file mode 100644
index 88e1dc7..0000000
--- a/net/base/file_stream_win.cc
+++ /dev/null
@@ -1,778 +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 "net/base/file_stream.h"
-
-#include <windows.h>
-
-#include "base/file_path.h"
-#include "base/logging.h"
-#include "base/message_loop.h"
-#include "base/metrics/histogram.h"
-#include "base/synchronization/waitable_event.h"
-#include "base/threading/thread_restrictions.h"
-#include "base/threading/worker_pool.h"
-#include "net/base/file_stream_metrics.h"
-#include "net/base/file_stream_net_log_parameters.h"
-#include "net/base/io_buffer.h"
-#include "net/base/net_errors.h"
-
-namespace net {
-
-// Ensure that we can just use our Whence values directly.
-COMPILE_ASSERT(FROM_BEGIN == FILE_BEGIN, bad_whence_begin);
-COMPILE_ASSERT(FROM_CURRENT == FILE_CURRENT, bad_whence_current);
-COMPILE_ASSERT(FROM_END == FILE_END, bad_whence_end);
-
-namespace {
-
-void SetOffset(OVERLAPPED* overlapped, const LARGE_INTEGER& offset) {
-  overlapped->Offset = offset.LowPart;
-  overlapped->OffsetHigh = offset.HighPart;
-}
-
-void IncrementOffset(OVERLAPPED* overlapped, DWORD count) {
-  LARGE_INTEGER offset;
-  offset.LowPart = overlapped->Offset;
-  offset.HighPart = overlapped->OffsetHigh;
-  offset.QuadPart += static_cast<LONGLONG>(count);
-  SetOffset(overlapped, offset);
-}
-
-int RecordAndMapError(int error,
-                      FileErrorSource source,
-                      bool record_uma,
-                      const net::BoundNetLog& bound_net_log) {
-  net::Error net_error = MapSystemError(error);
-
-  bound_net_log.AddEvent(
-      net::NetLog::TYPE_FILE_STREAM_ERROR,
-      base::Bind(&NetLogFileStreamErrorCallback,
-                 source, error, net_error));
-
-  RecordFileError(error, source, record_uma);
-
-  return net_error;
-}
-
-// Opens a file with some network logging.
-// The opened file and the result code are written to |file| and |result|.
-void OpenFile(const FilePath& path,
-              int open_flags,
-              bool record_uma,
-              base::PlatformFile* file,
-              int* result,
-              const net::BoundNetLog& bound_net_log) {
-  std::string file_name = path.AsUTF8Unsafe();
-  bound_net_log.BeginEvent(
-      net::NetLog::TYPE_FILE_STREAM_OPEN,
-      NetLog::StringCallback("file_name", &file_name));
-
-  *file = base::CreatePlatformFile(path, open_flags, NULL, NULL);
-  if (*file == base::kInvalidPlatformFileValue) {
-    DWORD error = GetLastError();
-    LOG(WARNING) << "Failed to open file: " << error;
-    *result = RecordAndMapError(error,
-                                FILE_ERROR_SOURCE_OPEN,
-                                record_uma,
-                                bound_net_log);
-    bound_net_log.EndEvent(net::NetLog::TYPE_FILE_STREAM_OPEN);
-    return;
-  }
-}
-
-// Closes a file with some network logging.
-void CloseFile(base::PlatformFile file,
-               const net::BoundNetLog& bound_net_log) {
-  bound_net_log.AddEvent(net::NetLog::TYPE_FILE_STREAM_CLOSE);
-  if (file == base::kInvalidPlatformFileValue)
-    return;
-
-  CancelIo(file);
-
-  if (!base::ClosePlatformFile(file))
-    NOTREACHED();
-  bound_net_log.EndEvent(net::NetLog::TYPE_FILE_STREAM_OPEN);
-}
-
-// Closes a file with CloseFile() and signals the completion.
-void CloseFileAndSignal(base::PlatformFile* file,
-                        base::WaitableEvent* on_io_complete,
-                        const net::BoundNetLog& bound_net_log) {
-  CloseFile(*file, bound_net_log);
-  *file = base::kInvalidPlatformFileValue;
-  on_io_complete->Signal();
-}
-
-// Invokes a given closure and signals the completion.
-void InvokeAndSignal(const base::Closure& closure,
-                     base::WaitableEvent* on_io_complete) {
-  closure.Run();
-  on_io_complete->Signal();
-}
-
-}  // namespace
-
-// FileStreamWin::AsyncContext ----------------------------------------------
-
-class FileStreamWin::AsyncContext : public MessageLoopForIO::IOHandler {
- public:
-  explicit AsyncContext(const net::BoundNetLog& bound_net_log)
-      : context_(), is_closing_(false),
-        record_uma_(false), bound_net_log_(bound_net_log),
-        error_source_(FILE_ERROR_SOURCE_COUNT) {
-    context_.handler = this;
-  }
-  ~AsyncContext();
-
-  void IOCompletionIsPending(const CompletionCallback& callback,
-                             IOBuffer* buf);
-
-  OVERLAPPED* overlapped() { return &context_.overlapped; }
-  const CompletionCallback& callback() const { return callback_; }
-
-  void set_error_source(FileErrorSource source) { error_source_ = source; }
-
-  void EnableErrorStatistics() {
-    record_uma_ = true;
-  }
-
- private:
-  virtual void OnIOCompleted(MessageLoopForIO::IOContext* context,
-                             DWORD bytes_read, DWORD error) OVERRIDE;
-
-  MessageLoopForIO::IOContext context_;
-  CompletionCallback callback_;
-  scoped_refptr<IOBuffer> in_flight_buf_;
-  bool is_closing_;
-  bool record_uma_;
-  const net::BoundNetLog bound_net_log_;
-  FileErrorSource error_source_;
-};
-
-FileStreamWin::AsyncContext::~AsyncContext() {
-  is_closing_ = true;
-  bool waited = false;
-  base::TimeTicks start = base::TimeTicks::Now();
-  while (!callback_.is_null()) {
-    waited = true;
-    MessageLoopForIO::current()->WaitForIOCompletion(INFINITE, this);
-  }
-  if (waited) {
-    // We want to see if we block the message loop for too long.
-    UMA_HISTOGRAM_TIMES("AsyncIO.FileStreamClose",
-                        base::TimeTicks::Now() - start);
-  }
-}
-
-void FileStreamWin::AsyncContext::IOCompletionIsPending(
-    const CompletionCallback& callback,
-    IOBuffer* buf) {
-  DCHECK(callback_.is_null());
-  callback_ = callback;
-  in_flight_buf_ = buf;  // Hold until the async operation ends.
-}
-
-void FileStreamWin::AsyncContext::OnIOCompleted(
-    MessageLoopForIO::IOContext* context, DWORD bytes_read, DWORD error) {
-  DCHECK_EQ(&context_, context);
-  DCHECK(!callback_.is_null());
-
-  if (is_closing_) {
-    callback_.Reset();
-    in_flight_buf_ = NULL;
-    return;
-  }
-
-  int result = static_cast<int>(bytes_read);
-  if (error && error != ERROR_HANDLE_EOF) {
-    result = RecordAndMapError(error, error_source_, record_uma_,
-                               bound_net_log_);
-  }
-
-  if (bytes_read)
-    IncrementOffset(&context->overlapped, bytes_read);
-
-  CompletionCallback temp_callback = callback_;
-  callback_.Reset();
-  scoped_refptr<IOBuffer> temp_buf = in_flight_buf_;
-  in_flight_buf_ = NULL;
-  temp_callback.Run(result);
-}
-
-// FileStream ------------------------------------------------------------
-
-FileStreamWin::FileStreamWin(net::NetLog* net_log)
-    : file_(base::kInvalidPlatformFileValue),
-      open_flags_(0),
-      auto_closed_(true),
-      record_uma_(false),
-      bound_net_log_(net::BoundNetLog::Make(net_log,
-                                            net::NetLog::SOURCE_FILESTREAM)),
-      weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
-  bound_net_log_.BeginEvent(net::NetLog::TYPE_FILE_STREAM_ALIVE);
-}
-
-FileStreamWin::FileStreamWin(
-    base::PlatformFile file, int flags, net::NetLog* net_log)
-    : file_(file),
-      open_flags_(flags),
-      auto_closed_(false),
-      record_uma_(false),
-      bound_net_log_(net::BoundNetLog::Make(net_log,
-                                            net::NetLog::SOURCE_FILESTREAM)),
-      weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
-  bound_net_log_.BeginEvent(net::NetLog::TYPE_FILE_STREAM_ALIVE);
-
-  // If the file handle is opened with base::PLATFORM_FILE_ASYNC, we need to
-  // make sure we will perform asynchronous File IO to it.
-  if (flags & base::PLATFORM_FILE_ASYNC) {
-    async_context_.reset(new AsyncContext(bound_net_log_));
-    MessageLoopForIO::current()->RegisterIOHandler(file_,
-                                                   async_context_.get());
-  }
-}
-
-FileStreamWin::~FileStreamWin() {
-  if (open_flags_ & base::PLATFORM_FILE_ASYNC) {
-    // Block until the in-flight open/close operation is complete.
-    // TODO(satorux): Ideally we should not block. crbug.com/115067
-    WaitForIOCompletion();
-
-    // Block until the last read/write operation is complete.
-    async_context_.reset();
-  }
-
-  if (auto_closed_) {
-    if (open_flags_ & base::PLATFORM_FILE_ASYNC) {
-      // Close the file in the background.
-      if (IsOpen()) {
-        const bool posted = base::WorkerPool::PostTask(
-            FROM_HERE,
-            base::Bind(&CloseFile, file_, bound_net_log_),
-            true /* task_is_slow */);
-        DCHECK(posted);
-      }
-    } else {
-      CloseSync();
-    }
-  }
-
-  bound_net_log_.EndEvent(net::NetLog::TYPE_FILE_STREAM_ALIVE);
-}
-
-void FileStreamWin::Close(const CompletionCallback& callback) {
-  DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
-  DCHECK(!weak_ptr_factory_.HasWeakPtrs());
-  DCHECK(!on_io_complete_.get());
-  on_io_complete_.reset(new base::WaitableEvent(
-      false  /* manual_reset */, false  /* initially_signaled */));
-
-  // Passing &file_ to a thread pool looks unsafe but it's safe here as the
-  // destructor ensures that the close operation is complete with
-  // WaitForIOCompletion(). See also the destructor.
-  const bool posted = base::WorkerPool::PostTaskAndReply(
-      FROM_HERE,
-      base::Bind(&CloseFileAndSignal, &file_, on_io_complete_.get(),
-                 bound_net_log_),
-      base::Bind(&FileStreamWin::OnClosed,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 callback),
-      true /* task_is_slow */);
-  DCHECK(posted);
-}
-
-void FileStreamWin::CloseSync() {
-  // The logic here is similar to CloseFile() but async_context_.reset() is
-  // caled in this function.
-
-  // Block until the in-flight open operation is complete.
-  // TODO(satorux): Replace this with a DCHECK(open_flags & ASYNC) once this
-  // once all async clients are migrated to use Close(). crbug.com/114783
-  WaitForIOCompletion();
-
-  bound_net_log_.AddEvent(net::NetLog::TYPE_FILE_STREAM_CLOSE);
-  if (file_ != base::kInvalidPlatformFileValue)
-    CancelIo(file_);
-
-  // Block until the last read/write operation is complete.
-  async_context_.reset();
-
-  if (file_ != base::kInvalidPlatformFileValue) {
-    if (!base::ClosePlatformFile(file_))
-      NOTREACHED();
-    file_ = base::kInvalidPlatformFileValue;
-
-    bound_net_log_.EndEvent(net::NetLog::TYPE_FILE_STREAM_OPEN);
-  }
-}
-
-int FileStreamWin::Open(const FilePath& path, int open_flags,
-                        const CompletionCallback& callback) {
-  if (IsOpen()) {
-    DLOG(FATAL) << "File is already open!";
-    return ERR_UNEXPECTED;
-  }
-
-  open_flags_ = open_flags;
-  DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
-  DCHECK(!weak_ptr_factory_.HasWeakPtrs());
-  DCHECK(!on_io_complete_.get());
-  on_io_complete_.reset(new base::WaitableEvent(
-      false  /* manual_reset */, false  /* initially_signaled */));
-
-  // Passing &file_ to a thread pool looks unsafe but it's safe here as the
-  // destructor ensures that the open operation is complete with
-  // WaitForIOCompletion().  See also the destructor.
-  int* result = new int(OK);
-  const bool posted = base::WorkerPool::PostTaskAndReply(
-      FROM_HERE,
-      base::Bind(&InvokeAndSignal,
-                 base::Bind(&OpenFile, path, open_flags, record_uma_, &file_,
-                            result, bound_net_log_),
-                 on_io_complete_.get()),
-      base::Bind(&FileStreamWin::OnOpened,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 callback, base::Owned(result)),
-      true /* task_is_slow */);
-  DCHECK(posted);
-  return ERR_IO_PENDING;
-}
-
-int FileStreamWin::OpenSync(const FilePath& path, int open_flags) {
-  if (IsOpen()) {
-    DLOG(FATAL) << "File is already open!";
-    return ERR_UNEXPECTED;
-  }
-
-  open_flags_ = open_flags;
-
-  int result = OK;
-  OpenFile(path, open_flags_, record_uma_, &file_, &result, bound_net_log_);
-  if (result != OK)
-    return result;
-
-  // TODO(satorux): Remove this once all async clients are migrated to use
-  // Open(). crbug.com/114783
-  if (open_flags_ & base::PLATFORM_FILE_ASYNC) {
-    async_context_.reset(new AsyncContext(bound_net_log_));
-    if (record_uma_)
-      async_context_->EnableErrorStatistics();
-    MessageLoopForIO::current()->RegisterIOHandler(file_,
-                                                   async_context_.get());
-  }
-
-  return OK;
-}
-
-bool FileStreamWin::IsOpen() const {
-  return file_ != base::kInvalidPlatformFileValue;
-}
-
-int FileStreamWin::Seek(Whence whence, int64 offset,
-                        const Int64CompletionCallback& callback) {
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  // Make sure we're async and we have no other in-flight async operations.
-  DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
-  DCHECK(!weak_ptr_factory_.HasWeakPtrs());
-  DCHECK(!on_io_complete_.get());
-
-  int64* result = new int64(-1);
-  on_io_complete_.reset(new base::WaitableEvent(
-      false  /* manual_reset */, false  /* initially_signaled */));
-
-  const bool posted = base::WorkerPool::PostTaskAndReply(
-      FROM_HERE,
-      base::Bind(&InvokeAndSignal,
-                 // Unretained should be fine as we wait for a signal on
-                 // on_io_complete_ at the destructor.
-                 base::Bind(&FileStreamWin::SeekFile, base::Unretained(this),
-                            whence, offset, result),
-                 on_io_complete_.get()),
-      base::Bind(&FileStreamWin::OnSeeked,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 callback, base::Owned(result)),
-      true /* task is slow */);
-  DCHECK(posted);
-  return ERR_IO_PENDING;
-}
-
-int64 FileStreamWin::SeekSync(Whence whence, int64 offset) {
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  DCHECK(!async_context_.get() || async_context_->callback().is_null());
-  int64 result = -1;
-  SeekFile(whence, offset, &result);
-  return result;
-}
-
-int64 FileStreamWin::Available() {
-  base::ThreadRestrictions::AssertIOAllowed();
-
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  int64 cur_pos = SeekSync(FROM_CURRENT, 0);
-  if (cur_pos < 0)
-    return cur_pos;
-
-  LARGE_INTEGER file_size;
-  if (!GetFileSizeEx(file_, &file_size)) {
-    DWORD error = GetLastError();
-    LOG(WARNING) << "GetFileSizeEx failed: " << error;
-    return RecordAndMapError(error,
-                             FILE_ERROR_SOURCE_GET_SIZE,
-                             record_uma_,
-                             bound_net_log_);
-  }
-
-  return file_size.QuadPart - cur_pos;
-}
-
-int FileStreamWin::Read(
-    IOBuffer* buf, int buf_len, const CompletionCallback& callback) {
-  DCHECK(async_context_.get());
-
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  DCHECK(open_flags_ & base::PLATFORM_FILE_READ);
-
-  OVERLAPPED* overlapped = NULL;
-  DCHECK(!callback.is_null());
-  DCHECK(async_context_->callback().is_null());
-  overlapped = async_context_->overlapped();
-  async_context_->set_error_source(FILE_ERROR_SOURCE_READ);
-
-  int rv = 0;
-
-  DWORD bytes_read;
-  if (!ReadFile(file_, buf->data(), buf_len, &bytes_read, overlapped)) {
-    DWORD error = GetLastError();
-    if (error == ERROR_IO_PENDING) {
-      async_context_->IOCompletionIsPending(callback, buf);
-      rv = ERR_IO_PENDING;
-    } else if (error == ERROR_HANDLE_EOF) {
-      rv = 0;  // Report EOF by returning 0 bytes read.
-    } else {
-      LOG(WARNING) << "ReadFile failed: " << error;
-      rv = RecordAndMapError(error,
-                             FILE_ERROR_SOURCE_READ,
-                             record_uma_,
-                             bound_net_log_);
-    }
-  } else if (overlapped) {
-    async_context_->IOCompletionIsPending(callback, buf);
-    rv = ERR_IO_PENDING;
-  } else {
-    rv = static_cast<int>(bytes_read);
-  }
-  return rv;
-}
-
-int FileStreamWin::ReadSync(char* buf, int buf_len) {
-  DCHECK(!async_context_.get());
-  base::ThreadRestrictions::AssertIOAllowed();
-
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  DCHECK(open_flags_ & base::PLATFORM_FILE_READ);
-
-  int rv = 0;
-
-  DWORD bytes_read;
-  if (!ReadFile(file_, buf, buf_len, &bytes_read, NULL)) {
-    DWORD error = GetLastError();
-    if (error == ERROR_HANDLE_EOF) {
-      rv = 0;  // Report EOF by returning 0 bytes read.
-    } else {
-      LOG(WARNING) << "ReadFile failed: " << error;
-      rv = RecordAndMapError(error,
-                             FILE_ERROR_SOURCE_READ,
-                             record_uma_,
-                             bound_net_log_);
-    }
-  } else {
-    rv = static_cast<int>(bytes_read);
-  }
-  return rv;
-}
-
-int FileStreamWin::ReadUntilComplete(char *buf, int buf_len) {
-  int to_read = buf_len;
-  int bytes_total = 0;
-
-  do {
-    int bytes_read = ReadSync(buf, to_read);
-    if (bytes_read <= 0) {
-      if (bytes_total == 0)
-        return bytes_read;
-
-      return bytes_total;
-    }
-
-    bytes_total += bytes_read;
-    buf += bytes_read;
-    to_read -= bytes_read;
-  } while (bytes_total < buf_len);
-
-  return bytes_total;
-}
-
-int FileStreamWin::Write(
-    IOBuffer* buf, int buf_len, const CompletionCallback& callback) {
-  DCHECK(async_context_.get());
-
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
-
-  OVERLAPPED* overlapped = NULL;
-  DCHECK(!callback.is_null());
-  DCHECK(async_context_->callback().is_null());
-  overlapped = async_context_->overlapped();
-  async_context_->set_error_source(FILE_ERROR_SOURCE_WRITE);
-
-  int rv = 0;
-  DWORD bytes_written = 0;
-  if (!WriteFile(file_, buf->data(), buf_len, &bytes_written, overlapped)) {
-    DWORD error = GetLastError();
-    if (error == ERROR_IO_PENDING) {
-      async_context_->IOCompletionIsPending(callback, buf);
-      rv = ERR_IO_PENDING;
-    } else {
-      LOG(WARNING) << "WriteFile failed: " << error;
-      rv = RecordAndMapError(error,
-                             FILE_ERROR_SOURCE_WRITE,
-                             record_uma_,
-                             bound_net_log_);
-    }
-  } else if (overlapped) {
-    async_context_->IOCompletionIsPending(callback, buf);
-    rv = ERR_IO_PENDING;
-  } else {
-    rv = static_cast<int>(bytes_written);
-  }
-  return rv;
-}
-
-int FileStreamWin::WriteSync(
-    const char* buf, int buf_len) {
-  DCHECK(!async_context_.get());
-  base::ThreadRestrictions::AssertIOAllowed();
-
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
-
-  int rv = 0;
-  DWORD bytes_written = 0;
-  if (!WriteFile(file_, buf, buf_len, &bytes_written, NULL)) {
-    DWORD error = GetLastError();
-    LOG(WARNING) << "WriteFile failed: " << error;
-    rv = RecordAndMapError(error,
-                           FILE_ERROR_SOURCE_WRITE,
-                           record_uma_,
-                           bound_net_log_);
-  } else {
-    rv = static_cast<int>(bytes_written);
-  }
-  return rv;
-}
-
-int FileStreamWin::Flush(const CompletionCallback& callback) {
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  // Make sure we're async and we have no other in-flight async operations.
-  DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
-  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
-  DCHECK(!weak_ptr_factory_.HasWeakPtrs());
-  DCHECK(!on_io_complete_.get());
-
-  on_io_complete_.reset(new base::WaitableEvent(
-      false  /* manual_reset */, false  /* initially_signaled */));
-
-  int* result = new int(OK);
-  const bool posted = base::WorkerPool::PostTaskAndReply(
-      FROM_HERE,
-      base::Bind(&InvokeAndSignal,
-                 // Unretained should be fine as we wait for a signal on
-                 // on_io_complete_ at the destructor.
-                 base::Bind(&FileStreamWin::FlushFile, base::Unretained(this),
-                            result),
-                 on_io_complete_.get()),
-      base::Bind(&FileStreamWin::OnFlushed,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 callback, base::Owned(result)),
-      true /* task is slow */);
-  DCHECK(posted);
-  return ERR_IO_PENDING;
-}
-
-int FileStreamWin::FlushSync() {
-  base::ThreadRestrictions::AssertIOAllowed();
-
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
-  if (FlushFileBuffers(file_)) {
-    return OK;
-  }
-
-  return RecordAndMapError(GetLastError(),
-                           FILE_ERROR_SOURCE_FLUSH,
-                           record_uma_,
-                           bound_net_log_);
-}
-
-int64 FileStreamWin::Truncate(int64 bytes) {
-  base::ThreadRestrictions::AssertIOAllowed();
-
-  if (!IsOpen())
-    return ERR_UNEXPECTED;
-
-  // We'd better be open for writing.
-  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
-
-  // Seek to the position to truncate from.
-  int64 seek_position = SeekSync(FROM_BEGIN, bytes);
-  if (seek_position != bytes)
-    return ERR_UNEXPECTED;
-
-  // And truncate the file.
-  BOOL result = SetEndOfFile(file_);
-  if (!result) {
-    DWORD error = GetLastError();
-    LOG(WARNING) << "SetEndOfFile failed: " << error;
-    return RecordAndMapError(error,
-                             FILE_ERROR_SOURCE_SET_EOF,
-                             record_uma_,
-                             bound_net_log_);
-  }
-
-  // Success.
-  return seek_position;
-}
-
-void FileStreamWin::EnableErrorStatistics() {
-  record_uma_ = true;
-
-  if (async_context_.get())
-    async_context_->EnableErrorStatistics();
-}
-
-void FileStreamWin::SetBoundNetLogSource(
-    const net::BoundNetLog& owner_bound_net_log) {
-  if ((owner_bound_net_log.source().id == net::NetLog::Source::kInvalidId) &&
-      (bound_net_log_.source().id == net::NetLog::Source::kInvalidId)) {
-    // Both |BoundNetLog|s are invalid.
-    return;
-  }
-
-  // Should never connect to itself.
-  DCHECK_NE(bound_net_log_.source().id, owner_bound_net_log.source().id);
-
-  bound_net_log_.AddEvent(
-      net::NetLog::TYPE_FILE_STREAM_BOUND_TO_OWNER,
-      owner_bound_net_log.source().ToEventParametersCallback());
-
-  owner_bound_net_log.AddEvent(
-      net::NetLog::TYPE_FILE_STREAM_SOURCE,
-      bound_net_log_.source().ToEventParametersCallback());
-}
-
-base::PlatformFile FileStreamWin::GetPlatformFileForTesting() {
-  return file_;
-}
-
-void FileStreamWin::OnClosed(const CompletionCallback& callback) {
-  file_ = base::kInvalidPlatformFileValue;
-
-  // Reset this before Run() as Run() may issue a new async operation.
-  ResetOnIOComplete();
-  callback.Run(OK);
-}
-
-void FileStreamWin::SeekFile(Whence whence, int64 offset, int64* result) {
-  LARGE_INTEGER distance, res;
-  distance.QuadPart = offset;
-  DWORD move_method = static_cast<DWORD>(whence);
-  if (!SetFilePointerEx(file_, distance, &res, move_method)) {
-    DWORD error = GetLastError();
-    LOG(WARNING) << "SetFilePointerEx failed: " << error;
-    *result = RecordAndMapError(error,
-                                FILE_ERROR_SOURCE_SEEK,
-                                record_uma_,
-                                bound_net_log_);
-    return;
-  }
-  if (async_context_.get()) {
-    async_context_->set_error_source(FILE_ERROR_SOURCE_SEEK);
-    SetOffset(async_context_->overlapped(), res);
-  }
-  *result = res.QuadPart;
-}
-
-void FileStreamWin::FlushFile(int* result) {
-  if (FlushFileBuffers(file_)) {
-    *result = OK;
-  } else {
-    *result = RecordAndMapError(GetLastError(),
-                                FILE_ERROR_SOURCE_FLUSH,
-                                record_uma_,
-                                bound_net_log_);
-  }
-}
-
-void FileStreamWin::OnOpened(const CompletionCallback& callback, int* result) {
-  if (*result == OK) {
-    async_context_.reset(new AsyncContext(bound_net_log_));
-    if (record_uma_)
-      async_context_->EnableErrorStatistics();
-    MessageLoopForIO::current()->RegisterIOHandler(file_,
-                                                   async_context_.get());
-  }
-
-  // Reset this before Run() as Run() may issue a new async operation.
-  ResetOnIOComplete();
-  callback.Run(*result);
-}
-
-void FileStreamWin::OnSeeked(
-    const Int64CompletionCallback& callback,
-    int64* result) {
-  // Reset this before Run() as Run() may issue a new async operation.
-  ResetOnIOComplete();
-  callback.Run(*result);
-}
-
-void FileStreamWin::OnFlushed(const CompletionCallback& callback, int* result) {
-  // Reset this before Run() as Run() may issue a new async operation.
-  ResetOnIOComplete();
-  callback.Run(*result);
-}
-
-void FileStreamWin::ResetOnIOComplete() {
-  on_io_complete_.reset();
-  weak_ptr_factory_.InvalidateWeakPtrs();
-}
-
-void FileStreamWin::WaitForIOCompletion() {
-  // http://crbug.com/115067
-  base::ThreadRestrictions::ScopedAllowWait allow_wait;
-  if (on_io_complete_.get()) {
-    on_io_complete_->Wait();
-    on_io_complete_.reset();
-  }
-}
-
-}  // namespace net
diff --git a/net/base/file_stream_win.h b/net/base/file_stream_win.h
deleted file mode 100644
index e241f4c..0000000
--- a/net/base/file_stream_win.h
+++ /dev/null
@@ -1,104 +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.
-
-// This file implements FileStream for Windows.
-
-#ifndef NET_BASE_FILE_STREAM_WIN_H_
-#define NET_BASE_FILE_STREAM_WIN_H_
-
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
-#include "base/platform_file.h"
-#include "base/synchronization/waitable_event.h"
-#include "net/base/completion_callback.h"
-#include "net/base/file_stream_whence.h"
-#include "net/base/net_export.h"
-#include "net/base/net_log.h"
-
-class FilePath;
-
-namespace base {
-class WaitableEvent;
-}
-
-namespace net {
-
-class IOBuffer;
-
-class NET_EXPORT FileStreamWin {
- public:
-  explicit FileStreamWin(net::NetLog* net_log);
-  FileStreamWin(base::PlatformFile file, int flags, net::NetLog* net_log);
-  ~FileStreamWin();
-
-  // FileStream implementations.
-  void Close(const CompletionCallback& callback);
-  void CloseSync();
-  int Open(const FilePath& path, int open_flags,
-           const CompletionCallback& callback);
-  int OpenSync(const FilePath& path, int open_flags);
-  bool IsOpen() const;
-  int Seek(Whence whence, int64 offset,
-           const Int64CompletionCallback& callback);
-  int64 SeekSync(Whence whence, int64 offset);
-  int64 Available();
-  int Read(IOBuffer* buf, int buf_len, const CompletionCallback& callback);
-  int ReadSync(char* buf, int buf_len);
-  int ReadUntilComplete(char *buf, int buf_len);
-  int Write(IOBuffer* buf, int buf_len, const CompletionCallback& callback);
-  int WriteSync(const char* buf, int buf_len);
-  int64 Truncate(int64 bytes);
-  int Flush(const CompletionCallback& callback);
-  int FlushSync();
-  void EnableErrorStatistics();
-  void SetBoundNetLogSource(const net::BoundNetLog& owner_bound_net_log);
-  base::PlatformFile GetPlatformFileForTesting();
-
- private:
-  class AsyncContext;
-
-  // A helper method for Seek.
-  void SeekFile(Whence whence, int64 offset, int64* result);
-
-  // A helper method for Flush.
-  void FlushFile(int* result);
-
-  // Called when the file_ is opened asynchronously. |result| contains the
-  // result as a network error code.
-  void OnOpened(const CompletionCallback& callback, int* result);
-
-  // Called when the file_ is closed asynchronously.
-  void OnClosed(const CompletionCallback& callback);
-
-  // Called when the file_ is seeked asynchronously.
-  void OnSeeked(const Int64CompletionCallback& callback, int64* result);
-
-  // Called when the file_ is flushed asynchronously.
-  void OnFlushed(const CompletionCallback& callback, int* result);
-
-  // Resets on_io_complete_ and WeakPtr's.
-  // Called in OnOpened, OnClosed and OnSeeked.
-  void ResetOnIOComplete();
-
-  // Waits until the in-flight async open/close operation is complete.
-  void WaitForIOCompletion();
-
-  // This member is used to support asynchronous reads.  It is non-null when
-  // the FileStreamWin was opened with PLATFORM_FILE_ASYNC.
-  scoped_ptr<AsyncContext> async_context_;
-
-  base::PlatformFile file_;
-  int open_flags_;
-  bool auto_closed_;
-  bool record_uma_;
-  net::BoundNetLog bound_net_log_;
-  base::WeakPtrFactory<FileStreamWin> weak_ptr_factory_;
-  scoped_ptr<base::WaitableEvent> on_io_complete_;
-
-  DISALLOW_COPY_AND_ASSIGN(FileStreamWin);
-};
-
-}  // namespace net
-
-#endif  // NET_BASE_FILE_STREAM_WIN_H_
diff --git a/net/base/net_log_event_type_list.h b/net/base/net_log_event_type_list.h
index 661fb6c..4cde922 100644
--- a/net/base/net_log_event_type_list.h
+++ b/net/base/net_log_event_type_list.h
@@ -1702,10 +1702,6 @@ EVENT_TYPE(FILE_STREAM_BOUND_TO_OWNER)
 //   }
 EVENT_TYPE(FILE_STREAM_OPEN)
 
-// This event is created when a file stream's Close() is called.
-// This may occur even when the file is not open.
-EVENT_TYPE(FILE_STREAM_CLOSE)
-
 // This event is created when a file stream operation has an error.
 //   {
 //     "operation": <open, write, close, etc>,
diff --git a/net/base/upload_file_element_reader.cc b/net/base/upload_file_element_reader.cc
index 11144e6..5658f21 100644
--- a/net/base/upload_file_element_reader.cc
+++ b/net/base/upload_file_element_reader.cc
@@ -41,7 +41,6 @@ int InitInternal(const FilePath& path,
     if (rv < 0) {
       DLOG(WARNING) << "Failed to seek \"" << path.value()
                     << "\" to offset: " << range_offset << " (" << rv << ")";
-      file_stream->CloseSync();
       file_stream.reset();
     }
   }
diff --git a/net/net.gyp b/net/net.gyp
index 98bc7ad..b3bd6a7 100644
--- a/net/net.gyp
+++ b/net/net.gyp
@@ -134,17 +134,17 @@
         'base/expiring_cache.h',
         'base/file_stream.cc',
         'base/file_stream.h',
+        'base/file_stream_context.cc',
+        'base/file_stream_context.h',
+        'base/file_stream_context_posix.cc',
+        'base/file_stream_context_win.cc',
         'base/file_stream_metrics.cc',
         'base/file_stream_metrics.h',
         'base/file_stream_metrics_posix.cc',
         'base/file_stream_metrics_win.cc',
         'base/file_stream_net_log_parameters.cc',
         'base/file_stream_net_log_parameters.h',
-        'base/file_stream_posix.cc',
-        'base/file_stream_posix.h',
         'base/file_stream_whence.h',
-        'base/file_stream_win.cc',
-        'base/file_stream_win.h',
         'base/filter.cc',
         'base/filter.h',
         'base/gzip_filter.cc',
diff --git a/net/url_request/url_request_file_job.cc b/net/url_request/url_request_file_job.cc
index 90512dc..c60b313 100644
--- a/net/url_request/url_request_file_job.cc
+++ b/net/url_request/url_request_file_job.cc
@@ -29,6 +29,7 @@
 #include "base/threading/thread_restrictions.h"
 #include "build/build_config.h"
 #include "googleurl/src/gurl.h"
+#include "net/base/file_stream.h"
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
 #include "net/base/mime_util.h"
@@ -90,7 +91,6 @@ URLRequestFileJob::URLRequestFileJob(URLRequest* request,
                                      const FilePath& file_path)
     : URLRequestJob(request, network_delegate),
       file_path_(file_path),
-      stream_(NULL),
       is_directory_(false),
       remaining_bytes_(0) {
 }
@@ -133,10 +133,7 @@ void URLRequestFileJob::Start() {
 }
 
 void URLRequestFileJob::Kill() {
-  // URL requests should not block on the disk!
-  //   http://code.google.com/p/chromium/issues/detail?id=59849
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
-  stream_.CloseSync();
+  stream_.reset();
 
   if (async_resolver_) {
     async_resolver_->Cancel();
@@ -162,9 +159,9 @@ bool URLRequestFileJob::ReadRawData(IOBuffer* dest, int dest_size,
     return true;
   }
 
-  int rv = stream_.Read(dest, dest_size,
-                        base::Bind(&URLRequestFileJob::DidRead,
-                                   base::Unretained(this)));
+  int rv = stream_->Read(dest, dest_size,
+                         base::Bind(&URLRequestFileJob::DidRead,
+                                    base::Unretained(this)));
   if (rv >= 0) {
     // Data is immediately available.
     *bytes_read = rv;
@@ -281,6 +278,8 @@ void URLRequestFileJob::DidResolve(
   if (!exists) {
     rv = ERR_FILE_NOT_FOUND;
   } else if (!is_directory_) {
+    stream_.reset(new FileStream(NULL));
+
     // URL requests should not block on the disk!
     //   http://code.google.com/p/chromium/issues/detail?id=59849
     base::ThreadRestrictions::ScopedAllowIO allow_io;
@@ -288,7 +287,7 @@ void URLRequestFileJob::DidResolve(
     int flags = base::PLATFORM_FILE_OPEN |
                 base::PLATFORM_FILE_READ |
                 base::PLATFORM_FILE_ASYNC;
-    rv = stream_.OpenSync(file_path_, flags);
+    rv = stream_->OpenSync(file_path_, flags);
   }
 
   if (rv != OK) {
@@ -314,7 +313,7 @@ void URLRequestFileJob::DidResolve(
     if (remaining_bytes_ > 0 &&
         byte_range_.first_byte_position() != 0 &&
         byte_range_.first_byte_position() !=
-        stream_.SeekSync(FROM_BEGIN, byte_range_.first_byte_position())) {
+        stream_->SeekSync(FROM_BEGIN, byte_range_.first_byte_position())) {
       NotifyDone(URLRequestStatus(URLRequestStatus::FAILED,
                                   ERR_REQUEST_RANGE_NOT_SATISFIABLE));
       return;
diff --git a/net/url_request/url_request_file_job.h b/net/url_request/url_request_file_job.h
index 4f34314..15c7d62 100644
--- a/net/url_request/url_request_file_job.h
+++ b/net/url_request/url_request_file_job.h
@@ -9,18 +9,22 @@
 #include <vector>
 
 #include "base/file_path.h"
-#include "net/base/file_stream.h"
 #include "net/base/net_export.h"
 #include "net/http/http_byte_range.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_job.h"
 
+namespace base{
+struct PlatformFileInfo;
+}
 namespace file_util {
 struct FileInfo;
 }
 
 namespace net {
 
+class FileStream;
+
 // A request job that handles reading file URLs
 class NET_EXPORT URLRequestFileJob : public URLRequestJob {
  public:
@@ -56,7 +60,7 @@ class NET_EXPORT URLRequestFileJob : public URLRequestJob {
   // Callback after data is asynchronously read from the file.
   void DidRead(int result);
 
-  FileStream stream_;
+  scoped_ptr<FileStream> stream_;
   bool is_directory_;
 
   HttpByteRange byte_range_;