Created an interface for DownloadFile, for use in unit tests.

content/browser/download/download_file_impl.cc

+// Copyright (c) 2011 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 "content/browser/download/download_file_impl.h"
+
+#include <string>
+
+#include "base/stringprintf.h"
+#include "content/browser/download/download_create_info.h"
+#include "content/browser/download/download_manager.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+DownloadFileImpl::DownloadFileImpl(
+    const DownloadCreateInfo* info,
+    DownloadRequestHandleInterface* request_handle,
+    DownloadManager* download_manager)
+    : file_(info->save_info.file_path,
+            info->url(),
+            info->referrer_url,
+            info->received_bytes,
+            info->save_info.file_stream),
+      id_(info->download_id),
+      request_handle_(request_handle),
+      download_manager_(download_manager) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+}
+
+DownloadFileImpl::~DownloadFileImpl() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+}
+
+// BaseFile delegated functions.
+net::Error DownloadFileImpl::Initialize(bool calculate_hash) {
+  return file_.Initialize(calculate_hash);
+}
+
+net::Error DownloadFileImpl::AppendDataToFile(const char* data,
+                                              size_t data_len) {
+  return file_.AppendDataToFile(data, data_len);
+}
+
+net::Error DownloadFileImpl::Rename(const FilePath& full_path) {
+  return file_.Rename(full_path);
+}
+
+void DownloadFileImpl::Detach() {
+  file_.Detach();
+}
+
+void DownloadFileImpl::Cancel() {
+  file_.Cancel();
+}
+
+void DownloadFileImpl::Finish() {
+  file_.Finish();
+}
+
+void DownloadFileImpl::AnnotateWithSourceInformation() {
+  file_.AnnotateWithSourceInformation();
+}
+
+FilePath DownloadFileImpl::FullPath() const {
+  return file_.full_path();
+}
+
+bool DownloadFileImpl::InProgress() const {
+  return file_.in_progress();
+}
+
+int64 DownloadFileImpl::BytesSoFar() const {
+  return file_.bytes_so_far();
+}
+
+bool DownloadFileImpl::GetSha256Hash(std::string* hash) {
+  return file_.GetSha256Hash(hash);
+}
+
+// DownloadFileInterface implementation.
+void DownloadFileImpl::CancelDownloadRequest() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  request_handle_->CancelRequest();
+}
+
+int DownloadFileImpl::Id() const {
+  return id_.local();
+}
+
+DownloadManager* DownloadFileImpl::GetDownloadManager() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  return download_manager_.get();
+}
+
+const DownloadId& DownloadFileImpl::GlobalId() const {
+  return id_;
+}
+
+std::string DownloadFileImpl::DebugString() const {
+  return base::StringPrintf("{"
+                            " id_ = " "%d"
+                            " request_handle = %s"
+                            " Base File = %s"
+                            " }",
+                            id_.local(),
+                            request_handle_->DebugString().c_str(),
+                            file_.DebugString().c_str());
+}