When the download folder does not exist, change the download folder to a user's "Downloads"

chrome/browser/download/download_manager.cc

Index: chrome/browser/download/download_manager.cc
diff --git a/chrome/browser/download/download_manager.cc b/chrome/browser/download/download_manager.cc
index 872464127f82afe8eae42a99d2600fd0e30ccbc8..3e0bdd9d0148bb2a353abce3a27a80554ccc6ad0 100644
--- a/chrome/browser/download/download_manager.cc
+++ b/chrome/browser/download/download_manager.cc
@@ -8,7 +8,6 @@
 #include "base/file_util.h"
 #include "base/i18n/case_conversion.h"
 #include "base/logging.h"
-#include "base/path_service.h"
 #include "base/rand_util.h"
 #include "base/stl_util-inl.h"
 #include "base/stringprintf.h"
@@ -365,33 +364,26 @@ void DownloadManager::CheckVisitedReferrerBeforeDone(
           &DownloadManager::CheckIfSuggestedPathExists,
           download->id(),
           state,
-          download_prefs()->download_path()));
+          download_prefs()->download_path(),
+          download_prefs()->GetDefaultDownloadDirectory()));
 }
 
-void DownloadManager::CheckIfSuggestedPathExists(int32 download_id,
-                                                 DownloadStateInfo state,
-                                                 const FilePath& default_path) {
+void DownloadManager::CheckIfSuggestedPathExists(
+    int32 download_id,
+    DownloadStateInfo state,
+    const FilePath& download_save_dir,
+    const FilePath& default_download_dir) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 
-  // Make sure the default download directory exists.
-  // TODO(phajdan.jr): only create the directory when we're sure the user
-  // is going to save there and not to another directory of his choice.
-  file_util::CreateDirectory(default_path);
-
-  // 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.
-  FilePath dir = state.suggested_path.DirName();
-  FilePath filename = state.suggested_path.BaseName();
-  if (!file_util::PathIsWritable(dir)) {
-    VLOG(1) << "Unable to write to directory \"" << dir.value() << "\"";
+  FilePath save_dir;
+  if (ChooseSavableDirectory(
+          FilePath(), download_save_dir, default_download_dir, &save_dir))
     state.prompt_user_for_save_location = true;
-    PathService::Get(chrome::DIR_USER_DOCUMENTS, &state.suggested_path);
-    state.suggested_path = state.suggested_path.Append(filename);
-  }
+  state.suggested_path = save_dir.Append(state.suggested_path.BaseName());
 
   // If the download is deemed dangerous, we'll use a temporary name for it.
   if (state.IsDangerous()) {
-    state.target_name = FilePath(state.suggested_path).BaseName();
+    state.target_name = state.suggested_path.BaseName();
     // Create a temporary file to hold the file until the user approves its
     // download.
     FilePath::StringType file_name;
@@ -410,7 +402,7 @@ void DownloadManager::CheckIfSuggestedPathExists(int32 download_id,
           unconfirmed_prefix.append(
               FILE_PATH_LITERAL(" %d.crdownload")).c_str(),
           base::RandInt(0, 100000));
-      path = dir.Append(file_name);
+      path = state.suggested_path.DirName().Append(file_name);
       if (file_util::PathExists(path))
         path = FilePath();
     }
@@ -500,7 +492,7 @@ void DownloadManager::OnPathExistenceAvailable(int32 download_id,
                                     contents, owning_window,
                                     reinterpret_cast<void*>(id_ptr));
     FOR_EACH_OBSERVER(Observer, observers_,
-                      SelectFileDialogDisplayed(download_id));
+                      SelectFileDialogDisplayed(download_id, suggested_path));
   } else {
     // No prompting for download, just continue with the suggested name.
     ContinueDownloadWithPath(download, suggested_path);
@@ -652,6 +644,40 @@ void DownloadManager::AssertNotInQueues(DownloadItem* download) {
   CHECK(!ContainsKey(history_downloads_, download->db_handle()));
 }
 
+// static
+bool DownloadManager::ChooseSavableDirectory(
+    const FilePath& website_save_dir,
+    const FilePath& download_save_dir,
+    const FilePath& default_download_dir,
+    FilePath* save_dir) {
+  bool prompt_dialog = false;
+  if (file_util::PathIsWritable(website_save_dir)) {
+    // If the default html/websites save folder exists,
+    // then use the default h5Btml/websites save folder.
+    *save_dir = website_save_dir;
+  } else if (file_util::PathIsWritable(download_save_dir)) {
+    // If the default html/websites save folder does not exist
+    // but the default download folder exists,
+    // then use the default download folder.
+    *save_dir = download_save_dir;
+  } else {
+    // If both the above folders do not exist,
+    // use the user's "Downloads" folder.
+    *save_dir = default_download_dir;
+    prompt_dialog = true;
+    if (!file_util::PathIsWritable(*save_dir)) {
+      VLOG(1) << "Cannot find the user's writable \"Downloads\" folder.";
+      // Create the |download_save_dir| folder if we cannot get
+      // the user's writable "Downloads" folder (This will be a rare case).
+      *save_dir = download_save_dir;
+    }
+    // Make sure that the folder does exist.
+    if (!file_util::CreateDirectory(*save_dir))
+      LOG(ERROR) << "Failed to create " << (*save_dir).value();
+  }
+  return prompt_dialog;
+}
+
 bool DownloadManager::IsDownloadReadyForCompletion(DownloadItem* download) {
   // If we don't have all the data, the download is not ready for
   // completion.