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

chrome/browser/history/history_types.cc

Index: chrome/browser/history/history_types.cc
diff --git a/chrome/browser/history/history_types.cc b/chrome/browser/history/history_types.cc
index 8447724a9b696e793783641048f4cbf61dea3c64..40648059ad5fa0a6fb635107a7d5172af0537d89 100644
--- a/chrome/browser/history/history_types.cc
+++ b/chrome/browser/history/history_types.cc
@@ -423,4 +423,14 @@ bool FaviconData::is_valid() {
   return known_icon && image_data.get() && image_data->size();
 }
 
+DownloadItemData::DownloadItemData()
+  : received_bytes(0),
+    state(0),
+    opened(false),
+    db_handle(-1) {
+}
+
+DownloadItemData::~DownloadItemData() {
+}
+
 }  // namespace history