Move most of the component updater artifacts to update_client.

components/update_client/crx_downloader.cc

Index: components/update_client/crx_downloader.cc
diff --git a/components/update_client/crx_downloader.cc b/components/update_client/crx_downloader.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ecbf301d8bd0a00cc57eed2300b16cf288b59bd4
--- /dev/null
+++ b/components/update_client/crx_downloader.cc
@@ -0,0 +1,157 @@
+// 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 "components/update_client/crx_downloader.h"
+
+#include "base/logging.h"
+#include "base/sequenced_task_runner.h"
+#include "base/single_thread_task_runner.h"
+#include "components/update_client/url_fetcher_downloader.h"
+
+#if defined(OS_WIN)
+#include "components/update_client/background_downloader_win.h"
+#endif
+
+namespace update_client {
+
+CrxDownloader::Result::Result()
+    : error(0), downloaded_bytes(-1), total_bytes(-1) {
+}
+
+CrxDownloader::DownloadMetrics::DownloadMetrics()
+    : downloader(kNone),
+      error(0),
+      downloaded_bytes(-1),
+      total_bytes(-1),
+      download_time_ms(0) {
+}
+
+// On Windows, the first downloader in the chain is a background downloader,
+// which uses the BITS service.
+CrxDownloader* CrxDownloader::Create(
+    bool is_background_download,
+    net::URLRequestContextGetter* context_getter,
+    scoped_refptr<base::SequencedTaskRunner> url_fetcher_task_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> background_task_runner) {
+  scoped_ptr<CrxDownloader> url_fetcher_downloader(
+      new UrlFetcherDownloader(scoped_ptr<CrxDownloader>().Pass(),
+                               context_getter, url_fetcher_task_runner));
+#if defined(OS_WIN)
+  if (is_background_download) {
+    return new BackgroundDownloader(url_fetcher_downloader.Pass(),
+                                    context_getter, background_task_runner);
+  }
+#endif
+
+  return url_fetcher_downloader.release();
+}
+
+CrxDownloader::CrxDownloader(scoped_ptr<CrxDownloader> successor)
+    : successor_(successor.Pass()) {
+}
+
+CrxDownloader::~CrxDownloader() {
+}
+
+void CrxDownloader::set_progress_callback(
+    const ProgressCallback& progress_callback) {
+  progress_callback_ = progress_callback;
+}
+
+GURL CrxDownloader::url() const {
+  return current_url_ != urls_.end() ? *current_url_ : GURL();
+}
+
+const std::vector<CrxDownloader::DownloadMetrics>
+CrxDownloader::download_metrics() const {
+  if (!successor_)
+    return download_metrics_;
+
+  std::vector<DownloadMetrics> retval(successor_->download_metrics());
+  retval.insert(retval.begin(), download_metrics_.begin(),
+                download_metrics_.end());
+  return retval;
+}
+
+void CrxDownloader::StartDownloadFromUrl(
+    const GURL& url,
+    const DownloadCallback& download_callback) {
+  std::vector<GURL> urls;
+  urls.push_back(url);
+  StartDownload(urls, download_callback);
+}
+
+void CrxDownloader::StartDownload(const std::vector<GURL>& urls,
+                                  const DownloadCallback& download_callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (urls.empty()) {
+    // Make a result and complete the download with a generic error for now.
+    Result result;
+    result.error = -1;
+    download_callback.Run(result);
+    return;
+  }
+
+  // If the urls are mutated while this downloader is active, then the
+  // behavior is undefined in the sense that the outcome of the download could
+  // be inconsistent for the list of urls. At any rate, the |current_url_| is
+  // reset at this point, and the iterator will be valid in all conditions.
+  urls_ = urls;
+  current_url_ = urls_.begin();
+  download_callback_ = download_callback;
+
+  DoStartDownload(*current_url_);
+}
+
+void CrxDownloader::OnDownloadComplete(
+    bool is_handled,
+    const Result& result,
+    const DownloadMetrics& download_metrics) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  download_metrics_.push_back(download_metrics);
+
+  if (result.error) {
+    // If an error has occured, in general try the next url if there is any,
+    // then move on to the successor in the chain if there is any successor.
+    // If this downloader has received a 5xx error for the current url,
+    // as indicated by the |is_handled| flag, remove that url from the list of
+    // urls so the url is never retried. In both cases, move on to the
+    // next url.
+    if (!is_handled) {
+      ++current_url_;
+    } else {
+      current_url_ = urls_.erase(current_url_);
+    }
+
+    // Try downloading from another url from the list.
+    if (current_url_ != urls_.end()) {
+      DoStartDownload(*current_url_);
+      return;
+    }
+
+    // If there is another downloader that can accept this request, then hand
+    // the request over to it so that the successor can try the pruned list
+    // of urls. Otherwise, the request ends here since the current downloader
+    // has tried all urls and it can't fall back on any other downloader.
+    if (successor_ && !urls_.empty()) {
+      successor_->StartDownload(urls_, download_callback_);
+      return;
+    }
+  }
+
+  download_callback_.Run(result);
+}
+
+void CrxDownloader::OnDownloadProgress(const Result& result) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (progress_callback_.is_null())
+    return;
+
+  progress_callback_.Run(result);
+}
+
+}  // namespace update_client