Add new UMA stats to get a handle on Downloads UI Usage

chrome/browser/download/download_history.cc

Index: chrome/browser/download/download_history.cc
diff --git a/chrome/browser/download/download_history.cc b/chrome/browser/download/download_history.cc
index 426a4345ff1717053737253bfb607ed3f27efaca..635e90cef426f36527f4aa41e0fad4780c831c31 100644
--- a/chrome/browser/download/download_history.cc
+++ b/chrome/browser/download/download_history.cc
@@ -113,6 +113,7 @@ void DownloadHistory::UpdateEntry(DownloadItem* download_item) {
 
   hs->UpdateDownload(download_item->received_bytes(),
                      download_item->state(),
+                     download_item->end_time(),
                      download_item->db_handle());
 }
 
@@ -162,3 +163,13 @@ void DownloadHistory::OnGotVisitCountToHost(HistoryService::Handle handle,
       (first_visit.LocalMidnight() < base::Time::Now().LocalMidnight()));
   delete callback;
 }
+
+void DownloadHistory::MarkDownloadOpened(int64 db_handle) {
+  // No update necessary if the download was initiated while in incognito mode.
+  if (db_handle <= DownloadItem::kUninitializedHandle)
+    return;
+
+  HistoryService* hs = profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
+  if (hs)
+    hs->MarkDownloadOpened(db_handle);
+}