Apply default wallpaper from customization manifest.

chrome/browser/chromeos/customization_wallpaper_downloader.h

+// 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_CUSTOMIZATION_WALLPAPER_DOWNLOADER_H_
+#define CHROME_BROWSER_CHROMEOS_CUSTOMIZATION_WALLPAPER_DOWNLOADER_H_
+
+#include <string>
+
+#include "base/bind.h"
+#include "base/files/file_path.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
+#include "net/url_request/url_fetcher_delegate.h"
+#include "url/gurl.h"
+
+namespace net {
+class URLRequestContextGetter;
+}  // namespace net
+
+namespace chromeos {
+
+// Download customized wallpaper.
+// Owner of this class must provide callback, which will be called on
+// finished (either successful or failed) wallpaper download.
+class CustomizationWallpaperDownloader : public net::URLFetcherDelegate {
+ public:
+  // - |url_context_getter| - Context to initialize net::URLFetcher.
+  // - |wallpaper_url| - wallpaper URL to download.
+  // - |wallpaper_dir| - directory, where wallpaper will be downloaded
+  // (it will be created).
+  // - |wallpaper_downloaded_file| - full path to local file to store downloaded
+  // wallpaper file. File is downloaded to temporary location
+  // |wallpaper_downloaded_file| + ".tmp", so directory must be writable.
+  // After download is completed, temporary file will be renamed to
+  // |wallpaper_downloaded_file|.
+  CustomizationWallpaperDownloader(
+      net::URLRequestContextGetter* url_context_getter,
+      const GURL& wallpaper_url,
+      const base::FilePath& wallpaper_dir,
+      const base::FilePath& wallpaper_downloaded_file,
+      base::Callback<void(bool success, const GURL&)>
+          on_wallpaper_fetch_completed);
+
+  virtual ~CustomizationWallpaperDownloader();
+
+  // Start download.
+  void Start();
+
+  // net::URLFetcherDelegate
+  virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
+
+ private:
+  // Start new request.
+  void StartRequest();
+
+  // Schedules retry.
+  void Retry();
+
+  // Called on UI thread.
+  void OnWallpaperDirectoryCreated(scoped_ptr<bool> success);
+
+  // Called on UI thread.
+  void OnTemporaryFileRenamed(scoped_ptr<bool> success);
+
+  // This is used to initialize net::URLFetcher object.
+  scoped_refptr<net::URLRequestContextGetter> url_context_getter_;
+
+  // This fetcher is used to download wallpaper file.
+  scoped_ptr<net::URLFetcher> url_fetcher_;
+
+  // The wallpaper URL to fetch.
+  const GURL wallpaper_url_;
+
+  // Wallpaper directory (to be created).
+  const base::FilePath wallpaper_dir_;
+
+  // Full path to local file to save downloaded wallpaper.
+  const base::FilePath wallpaper_downloaded_file_;
+
+  // Full path to temporary file to fetch downloaded wallpper.
+  const base::FilePath wallpaper_temporary_file_;
+
+  // Pending retry.
+  base::OneShotTimer<CustomizationWallpaperDownloader> request_scheduled_;
+
+  // Number of download retries (first attempt is not counted as retry).
+  size_t retries_;
+
+  // Callback supplied by caller.
+  base::Callback<void(bool success, const GURL&)> on_wallpaper_fetch_completed_;
+
+  base::WeakPtrFactory<CustomizationWallpaperDownloader> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(CustomizationWallpaperDownloader);
+};
+
+}  //   namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_CUSTOMIZATION_WALLPAPER_DOWNLOADER_H_