MD Settings: Add "Auto Open" setting to Downloads page UI.

chrome/browser/ui/webui/settings/downloads_handler.cc

Index: chrome/browser/ui/webui/settings/downloads_handler.cc
diff --git a/chrome/browser/ui/webui/settings/downloads_handler.cc b/chrome/browser/ui/webui/settings/downloads_handler.cc
index 93e74d88de1e6f180bde4fd841719901994df021..72d30c69992c480df35bd38c39dab454e1fb8ece 100644
--- a/chrome/browser/ui/webui/settings/downloads_handler.cc
+++ b/chrome/browser/ui/webui/settings/downloads_handler.cc
@@ -36,6 +36,10 @@ void DownloadsHandler::RegisterMessages() {
       "initializeDownloads",

[Dan Beam, 2017/02/27 05:50:36]

where is this already called?  was this just unused code until now?

[tommycli, 2017/02/28 00:47:26]

Yes, added in the previous CL, used in this CL for the first time.

       base::Bind(&DownloadsHandler::HandleInitialize, base::Unretained(this)));
   web_ui()->RegisterMessageCallback(
+      "resetAutoOpenFileTypes",
+      base::Bind(&DownloadsHandler::HandleResetAutoOpenFileTypes,
+                 base::Unretained(this)));
+  web_ui()->RegisterMessageCallback(
       "selectDownloadLocation",
       base::Bind(&DownloadsHandler::HandleSelectDownloadLocation,
                  base::Unretained(this)));
@@ -68,6 +72,15 @@ void DownloadsHandler::SendAutoOpenDownloadsToJavascript() {
                          base::FundamentalValue(auto_open_downloads));
 }
 
+void DownloadsHandler::HandleResetAutoOpenFileTypes(
+    const base::ListValue* args) {
+  content::RecordAction(UserMetricsAction("Options_ResetAutoOpenFiles"));
+  content::DownloadManager* manager =
+      content::BrowserContext::GetDownloadManager(profile_);
+  if (manager)
+    DownloadPrefs::FromDownloadManager(manager)->ResetAutoOpen();
+}
+
 void DownloadsHandler::HandleSelectDownloadLocation(
     const base::ListValue* args) {
   PrefService* pref_service = profile_->GetPrefs();