Use the user's preferred downloads directory for creating the initial download file.

content/browser/download/save_file.cc

Index: content/browser/download/save_file.cc
diff --git a/content/browser/download/save_file.cc b/content/browser/download/save_file.cc
index b4474d10df9700348856e5e3a39be2c22a813619..b0bd5b403030846e4e090555391c61b3ee62bca3 100644
--- a/content/browser/download/save_file.cc
+++ b/content/browser/download/save_file.cc
@@ -6,12 +6,19 @@
 
 #include "base/logging.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/content_browser_client.h"
 #include "net/base/file_stream.h"
 
 using content::BrowserThread;
 
+// TODO(asanka): SaveFile should use the target directory of the save package as
+//               the default download directory when initializing |file_|.
+//               Unfortunately, as it is, constructors of SaveFile doesn't
+//               always have access to the SavePackage at this point.
 SaveFile::SaveFile(const SaveFileCreateInfo* info, bool calculate_hash)
-    : file_(FilePath(),
+    : file_(content::GetContentClient()->browser()->
+                GetDefaultDownloadDirectory(),

[Randy Smith (Not in Mondays), 2012/09/14 16:38:16]

Is this safe to access on the file thread?

[asanka, 2012/09/14 19:11:45]

It's documented as "can be called on any thread."

+            FilePath(),
             info->url,
             GURL(),
             0,