Remove unused parts of //mojo/common.

mojo/common/data_pipe_file_utils.cc

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "mojo/common/data_pipe_utils.h"
-
-#include <stdint.h>
-
-#include "base/files/file_path.h"
-#include "base/files/file_util.h"
-#include "base/files/scoped_file.h"
-#include "base/location.h"
-#include "base/task_runner_util.h"
-
-namespace mojo {
-namespace common {
-namespace {
-
-bool BlockingCopyFromFile(const base::FilePath& source,
-                          ScopedDataPipeProducerHandle destination,
-                          uint32_t skip) {
-  base::File file(source, base::File::FLAG_OPEN | base::File::FLAG_READ);
-  if (!file.IsValid())
-    return false;
-  if (file.Seek(base::File::FROM_BEGIN, skip) != skip) {
-    LOG(ERROR) << "Seek of " << skip << " in " << source.value() << " failed";
-    return false;
-  }
-  for (;;) {
-    void* buffer = nullptr;
-    uint32_t buffer_num_bytes = 0;
-    MojoResult result =
-        BeginWriteDataRaw(destination.get(), &buffer, &buffer_num_bytes,
-                          MOJO_WRITE_DATA_FLAG_NONE);
-    if (result == MOJO_RESULT_OK) {
-      int bytes_read =
-          file.ReadAtCurrentPos(static_cast<char*>(buffer), buffer_num_bytes);
-      if (bytes_read >= 0) {
-        EndWriteDataRaw(destination.get(), bytes_read);
-        if (bytes_read == 0) {
-          // eof
-          return true;
-        }
-      } else {
-        // error
-        EndWriteDataRaw(destination.get(), 0);
-        return false;
-      }
-    } else if (result == MOJO_RESULT_SHOULD_WAIT) {
-      result = Wait(destination.get(), MOJO_HANDLE_SIGNAL_WRITABLE,
-                    MOJO_DEADLINE_INDEFINITE, nullptr);
-      if (result != MOJO_RESULT_OK) {
-        // If the consumer handle was closed, then treat as EOF.
-        return result == MOJO_RESULT_FAILED_PRECONDITION;
-      }
-    } else {
-      // If the consumer handle was closed, then treat as EOF.
-      return result == MOJO_RESULT_FAILED_PRECONDITION;
-    }
-  }
-#if !defined(OS_WIN)
-  NOTREACHED();
-  return false;
-#endif
-}
-
-}  // namespace
-
-void CopyFromFile(const base::FilePath& source,
-                  ScopedDataPipeProducerHandle destination,
-                  uint32_t skip,
-                  base::TaskRunner* task_runner,
-                  const base::Callback<void(bool)>& callback) {
-  base::PostTaskAndReplyWithResult(task_runner, FROM_HERE,
-                                   base::Bind(&BlockingCopyFromFile, source,
-                                              base::Passed(&destination), skip),
-                                   callback);
-}
-
-}  // namespace common
-}  // namespace mojo