Refactor dangerous download warning text generation into DownloadItemModel.

chrome/browser/ui/cocoa/download/download_item_mac.mm

Index: chrome/browser/ui/cocoa/download/download_item_mac.mm
diff --git a/chrome/browser/ui/cocoa/download/download_item_mac.mm b/chrome/browser/ui/cocoa/download/download_item_mac.mm
index 832219692e07e711152143dffd2e7809cc421610..380e6c16548b66ecc79de6135ee50b305239bfda 100644
--- a/chrome/browser/ui/cocoa/download/download_item_mac.mm
+++ b/chrome/browser/ui/cocoa/download/download_item_mac.mm
@@ -30,8 +30,7 @@ DownloadItemMac::~DownloadItemMac() {
 void DownloadItemMac::OnDownloadUpdated(content::DownloadItem* download) {
   DCHECK_EQ(download, download_model_->download());
 
-  if ([item_controller_ isDangerousMode] &&
-      download->GetSafetyState() == DownloadItem::DANGEROUS_BUT_VALIDATED) {
+  if ([item_controller_ isDangerousMode] && !download_model_->IsDangerous()) {
     // We have been approved.
     [item_controller_ clearDangerousMode];
   }