Show download error message if sdcard is not available

chrome/browser/download/download_path_reservation_tracker.cc

 // Copyright (c) 2012 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 "chrome/browser/download/download_path_reservation_tracker.h"
 
 #include <stddef.h>
 
 #include <map>
 
@@ skipping 146 matching lines @@
 // - Returns true if |reserved_path| has been successfully verified.
 bool CreateReservation(
     ReservationKey key,
     const base::FilePath& suggested_path,
     const base::FilePath& default_download_path,
     bool create_directory,
     DownloadPathReservationTracker::FilenameConflictAction conflict_action,
     base::FilePath* reserved_path) {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
   DCHECK(suggested_path.IsAbsolute());
-
   // Create a reservation map if one doesn't exist. It will be automatically
   // deleted when all the reservations are revoked.
   if (g_reservation_map == NULL)
     g_reservation_map = new ReservationMap;
   ReservationMap& reservations = *g_reservation_map;
 
   // Erase the reservation if it already exists. This can happen during
   // automatic resumption where a new target determination request may be issued
   // for a DownloadItem without an intervening transition to INTERRUPTED.
   //
@@ skipping 17 matching lines @@
       (create_directory ||
        (!default_download_path.empty() &&
         (default_download_path == target_dir)))) {
     base::CreateDirectory(target_dir);
   }
 
   // Check writability of the suggested path. If we can't write to it, default
   // to the user's "My Documents" directory. We'll prompt them in this case.
   if (!base::PathIsWritable(target_dir)) {
     DVLOG(1) << "Unable to write to directory \"" << target_dir.value() << "\"";
+#if defined(OS_ANDROID)

[asanka, 2016/07/07 21:12:48]

This code is conditioned on OS_ANDROID while the only logic that intercepts the
resulting state (!verified && path.empty()) is conditioned on
BUILDFLAG(ANDROID_JAVA_UI). Let's pick one.

[qinmin, 2016/07/07 22:49:37]

Done.

+    // On Android, file will not be by other apps if it is downloaded to
+    // Chrome's own directory.

[asanka, 2016/07/07 21:12:48]

The comment should mention that DIR_USER_DOCUMENTS is in reality a subdirectory
of DIR_ANDROID_APP_DATA which isn't accessible by other apps.

Also explicitly clear |reserved_path| here.

[qinmin, 2016/07/07 22:49:37]

Done.

+    return false;
+#else
     is_path_writeable = false;
     PathService::Get(chrome::DIR_USER_DOCUMENTS, &target_dir);
     target_path = target_dir.Append(filename);
+#endif
   }
 
   if (is_path_writeable) {
     // Check the limit of file name length if it could be obtained. When the
     // suggested name exceeds the limit, truncate or prompt the user.
     int max_length = base::GetMaximumPathComponentLength(target_dir);
     if (max_length != -1) {
       int limit = max_length - kIntermediateNameSuffixLength;
       if (limit <= 0 || !TruncateFileName(&target_path, limit))
         name_too_long = true;
@@ skipping 171 matching lines @@
       base::Bind(&RunGetReservedPathCallback,
                  callback,
                  base::Owned(reserved_path)));
 }
 
 // static
 bool DownloadPathReservationTracker::IsPathInUseForTesting(
     const base::FilePath& path) {
   return IsPathInUse(path);
 }