Fix an issue that temp files are left permanently on storage after chrome crash

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 49262d0d42d9fca3591ac486b2b6a0d48e259efc..5e2e7e38b069bd5b4cc22bd934db236c82d77448 100644
--- a/chrome/browser/download/download_history.cc
+++ b/chrome/browser/download/download_history.cc
@@ -163,6 +163,18 @@ bool ShouldUpdateHistory(const history::DownloadRow* previous,
           (previous->by_ext_name != current.by_ext_name));
 }
 
+bool ShouldCommitHistoryImmediately(const history::DownloadRow* previous,
+                                    const history::DownloadRow& current) {

[asanka, 2016/11/16 23:15:57]

Minor nit: You could fold this into ShouldUpdateHistory above. It can return a
3-state instead of a bool. I.e. NO, UPDATE, UPDATE_AND_COMMIT_IMMEDIATELY or
somesuch.

[qinmin, 2016/11/17 00:46:30]

Done.

+#if defined(OS_ANDROID)

[asanka, 2016/11/16 23:15:57]

Let's make this work on all platforms.

[qinmin, 2016/11/17 00:46:30]

Done.

+  // When download path is determined, Chrome should commit the history
+  // immediately. Otherwise the file will be left permanently on the external
+  // storage if Chrome crashes right away.
+  return (previous != nullptr) &&
+      (previous->current_path.empty() && !current.current_path.empty());
+#endif
+  return false;
+}
+
 typedef std::vector<history::DownloadRow> InfoVector;
 
 }  // anonymous namespace
@@ -185,8 +197,8 @@ void DownloadHistory::HistoryAdapter::CreateDownload(
 }
 
 void DownloadHistory::HistoryAdapter::UpdateDownload(
-    const history::DownloadRow& data) {
-  history_->UpdateDownload(data);
+    const history::DownloadRow& data, bool should_commit_immediately) {
+  history_->UpdateDownload(data, should_commit_immediately);
 }
 
 void DownloadHistory::HistoryAdapter::RemoveDownloads(
@@ -411,7 +423,9 @@ void DownloadHistory::OnDownloadUpdated(
   UMA_HISTOGRAM_ENUMERATION("Download.HistoryPropagatedUpdate",
                             should_update, 2);
   if (should_update) {
-    history_->UpdateDownload(current_info);
+    history_->UpdateDownload(
+        current_info,
+        ShouldCommitHistoryImmediately(data->info(), current_info));
     for (Observer& observer : observers_)
       observer.OnDownloadStored(item, current_info);
   }