Added a link to the downloads tab that opens the downloads folder.

chrome/browser/ui/webui/downloads_dom_handler.cc

Index: chrome/browser/ui/webui/downloads_dom_handler.cc
diff --git a/chrome/browser/ui/webui/downloads_dom_handler.cc b/chrome/browser/ui/webui/downloads_dom_handler.cc
index f5e7929ce49d63f00a34573c4dad7fb57e61c438..d31777132b3709b944bcf7a9572892559f9fb786 100644
--- a/chrome/browser/ui/webui/downloads_dom_handler.cc
+++ b/chrome/browser/ui/webui/downloads_dom_handler.cc
@@ -17,7 +17,9 @@
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/download/download_history.h"
 #include "chrome/browser/download/download_item.h"
+#include "chrome/browser/download/download_prefs.h"
 #include "chrome/browser/download/download_util.h"
+#include "chrome/browser/platform_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/webui/chrome_url_data_manager.h"
 #include "chrome/browser/ui/webui/fileicon_source.h"
@@ -97,6 +99,8 @@ void DownloadsDOMHandler::RegisterMessages() {
       NewCallback(this, &DownloadsDOMHandler::HandleCancel));
   web_ui_->RegisterMessageCallback("clearAll",
       NewCallback(this, &DownloadsDOMHandler::HandleClearAll));
+  web_ui_->RegisterMessageCallback("openDownloadsFolder",
+      NewCallback(this, &DownloadsDOMHandler::HandleOpenDownloadsFolder));
 }
 
 void DownloadsDOMHandler::OnDownloadUpdated(DownloadItem* download) {
@@ -227,6 +231,19 @@ void DownloadsDOMHandler::HandleClearAll(const ListValue* args) {
   download_manager_->RemoveAllDownloads();
 }
 
+void DownloadsDOMHandler::HandleOpenDownloadsFolder(const ListValue* args) {
+  FilePath path = download_manager_->download_prefs()->download_path();
+
+#if defined(OS_MACOSX)
+  // Must be called from the UI thread on Mac.
+  platform_util::OpenItem(path);
+#else
+  BrowserThread::PostTask(
+      BrowserThread::FILE, FROM_HERE,
+      NewRunnableFunction(&platform_util::OpenItem, path));
+#endif
+}
+
 // DownloadsDOMHandler, private: ----------------------------------------------
 
 void DownloadsDOMHandler::SendCurrentDownloads() {