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

chrome/browser/history/history_backend.cc

Index: chrome/browser/history/history_backend.cc
diff --git a/chrome/browser/history/history_backend.cc b/chrome/browser/history/history_backend.cc
index 9ffc50466df917a0a26b78f70db54c623fe6be9c..2ac8dc1a548b5a2787276bd55c49ded6dd4da1f7 100644
--- a/chrome/browser/history/history_backend.cc
+++ b/chrome/browser/history/history_backend.cc
@@ -1120,9 +1120,10 @@ void HistoryBackend::CleanUpInProgressEntries() {
 // Update a particular download entry.
 void HistoryBackend::UpdateDownload(int64 received_bytes,
                                     int32 state,
+                                    const base::Time& end_time,
                                     int64 db_handle) {
   if (db_.get())
-    db_->UpdateDownload(received_bytes, state, db_handle);
+    db_->UpdateDownload(received_bytes, state, end_time, db_handle);
 }
 
 // Update the path of a particular download entry.
@@ -1156,6 +1157,11 @@ void HistoryBackend::RemoveDownloadsBetween(const Time remove_begin,
     db_->RemoveDownloadsBetween(remove_begin, remove_end);
 }
 
+void HistoryBackend::MarkDownloadOpened(int64 db_handle) {
+  if (db_.get())
+    db_->MarkDownloadOpened(db_handle);
+}
+
 void HistoryBackend::QueryHistory(scoped_refptr<QueryHistoryRequest> request,
                                   const string16& text_query,
                                   const QueryOptions& options) {