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

chrome/browser/download/save_package.cc

Index: chrome/browser/download/save_package.cc
diff --git a/chrome/browser/download/save_package.cc b/chrome/browser/download/save_package.cc
index 81bdfcfdfe5a2dd5d252165196836d0e304fa532..fb7d77cb94be3acc03e2a10727de3bdfdda16dd5 100644
--- a/chrome/browser/download/save_package.cc
+++ b/chrome/browser/download/save_package.cc
@@ -1256,35 +1256,38 @@ FilePath SavePackage::GetSaveDirPreference(PrefService* prefs) {
 }
 
 void SavePackage::GetSaveInfo() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
   // Can't use tab_contents_ in the file thread, so get the data that we need
   // before calling to it.
   PrefService* prefs = tab_contents()->profile()->GetPrefs();
   FilePath website_save_dir = GetSaveDirPreference(prefs);
   FilePath download_save_dir = prefs->GetFilePath(
       prefs::kDownloadDefaultDirectory);
+  DownloadPrefs* download_prefs =
+      tab_contents()->profile()->GetDownloadManager()->download_prefs();
+  FilePath default_download_dir = download_prefs->GetDefaultDownloadDirectory();
   std::string mime_type = tab_contents()->contents_mime_type();
 
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       NewRunnableMethod(this, &SavePackage::CreateDirectoryOnFileThread,
-          website_save_dir, download_save_dir, mime_type));
+                        website_save_dir, download_save_dir,
+                        default_download_dir, mime_type));
 }
 
 void SavePackage::CreateDirectoryOnFileThread(
     const FilePath& website_save_dir,
     const FilePath& download_save_dir,
+    const FilePath& default_download_dir,
     const std::string& mime_type) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+
   FilePath save_dir;
-  // If the default html/websites save folder doesn't exist...
-  if (!file_util::DirectoryExists(website_save_dir)) {
-    // If the default download dir doesn't exist, create it.
-    if (!file_util::DirectoryExists(download_save_dir))
-      file_util::CreateDirectory(download_save_dir);
-    save_dir = download_save_dir;
-  } else {
-    // If it does exist, use the default save dir param.
-    save_dir = website_save_dir;
-  }
+  // Ignores the returned value since the select file dialog should be
+  // displayed in any case.
+  DownloadManager::ChooseSavableDirectory(
+      website_save_dir, download_save_dir, default_download_dir, &save_dir);
 
   bool can_save_as_complete = CanSaveAsComplete(mime_type);
   FilePath suggested_filename = GetSuggestedNameForSaveAs(can_save_as_complete,
@@ -1314,6 +1317,8 @@ void SavePackage::CreateDirectoryOnFileThread(
 
 void SavePackage::ContinueGetSaveInfo(const FilePath& suggested_path,
                                       bool can_save_as_complete) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
   // The TabContents which owns this SavePackage may have disappeared during
   // the UI->FILE->UI thread hop of
   // GetSaveInfo->CreateDirectoryOnFileThread->ContinueGetSaveInfo.
@@ -1403,6 +1408,8 @@ void SavePackage::ContinueGetSaveInfo(const FilePath& suggested_path,
 // Called after the save file dialog box returns.
 void SavePackage::ContinueSave(const FilePath& final_name,
                                int index) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
   // Ensure the filename is safe.
   saved_main_file_path_ = final_name;
   download_util::GenerateSafeFileName(tab_contents()->contents_mime_type(),