Give Background Fetch downloads an explicit path on Android

content/browser/background_fetch/background_fetch_job_controller.cc

 // Copyright 2017 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/background_fetch/background_fetch_job_controller.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "content/browser/background_fetch/background_fetch_constants.h"
 #include "content/browser/background_fetch/background_fetch_data_manager.h"
 #include "content/common/service_worker/service_worker_types.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/browser/download_manager.h"
 #include "net/url_request/url_request_context_getter.h"
 
+#if defined(OS_ANDROID)
+#include "base/android/path_utils.h"
+#include "base/files/file_path.h"
+#include "base/guid.h"
+#endif
+
 namespace content {
 
+#if defined(OS_ANDROID)
+namespace {
+
+// Prefix for files stored in the Chromium-internal download directory to
+// indicate files thta were fetched through Background Fetch.

[shaktisahu, 2017/04/18 20:16:56]

nit: typo

+const char kBackgroundFetchFilePrefix[] = "BGFetch-";
+
+}  // namespace
+#endif  // defined(OS_ANDROID)
+
 // Internal functionality of the BackgroundFetchJobController that lives on the
 // UI thread, where all interaction with the download manager must happen.
 class BackgroundFetchJobController::Core : public DownloadItem::Observer {
  public:
   Core(const base::WeakPtr<BackgroundFetchJobController>& io_parent,
        BrowserContext* browser_context,
        scoped_refptr<net::URLRequestContextGetter> request_context)
       : io_parent_(io_parent),
         browser_context_(browser_context),
         request_context_(std::move(request_context)),
@@ skipping 19 matching lines @@
 
     const ServiceWorkerFetchRequest& fetch_request = request->fetch_request();
 
     std::unique_ptr<DownloadUrlParameters> download_parameters(
         base::MakeUnique<DownloadUrlParameters>(fetch_request.url,
                                                 request_context_.get()));
 
     // TODO(peter): The |download_parameters| should be populated with all the
     // properties set in the |fetch_request| structure.
 
+    // TODO(peter): Background Fetch responses should not end up in the user's
+    // download folder on any platform. Find an appropriate solution for desktop
+    // too. The Android internal directory is not scoped to a profile.
+
     download_parameters->set_transient(true);
+
+#if defined(OS_ANDROID)
+    base::FilePath download_directory;
+    if (base::android::GetDownloadInternalDirectory(&download_directory)) {
+      download_parameters->set_file_path(download_directory.Append(
+          std::string(kBackgroundFetchFilePrefix) + base::GenerateGUID()));
+    }
+#endif  // defined(OS_ANDROID)
+
     download_parameters->set_callback(base::Bind(&Core::DidStartRequest,
                                                  weak_ptr_factory_.GetWeakPtr(),
                                                  std::move(request)));
 
     download_manager->DownloadUrl(std::move(download_parameters));
   }
 
   // DownloadItem::Observer overrides:
   void OnDownloadUpdated(DownloadItem* download_item) override {
     DCHECK_CURRENTLY_ON(BrowserThread::UI);
@@ skipping 190 matching lines @@
 
   // TODO(harkness): Abort all in-progress downloads.
 
   state_ = State::ABORTED;
 
   // Inform the owner of the controller about the job having completed.
   std::move(completed_callback_).Run(this);
 }
 
 }  // namespace content