Don't leak WebHistoryService::Request on HistoryService shutdown.

chrome/browser/ui/webui/history_ui.cc

Index: chrome/browser/ui/webui/history_ui.cc
diff --git a/chrome/browser/ui/webui/history_ui.cc b/chrome/browser/ui/webui/history_ui.cc
index 7f9a513c507431e8ad30ad43a66a80efe063d06f..44a511d6563fb0b75233abeac5099dc95ffb730a 100644
--- a/chrome/browser/ui/webui/history_ui.cc
+++ b/chrome/browser/ui/webui/history_ui.cc
@@ -386,7 +386,10 @@ bool BrowsingHistoryHandler::HistoryEntry::SortByTimeDescending(
   return entry1.time > entry2.time;
 }
 
-BrowsingHistoryHandler::BrowsingHistoryHandler() {}
+BrowsingHistoryHandler::BrowsingHistoryHandler()
+    : pending_delete_requests_(0),
+      weak_factory_(this) {
+}
 
 BrowsingHistoryHandler::~BrowsingHistoryHandler() {
   history_request_consumer_.CancelAllRequests();
@@ -612,10 +615,11 @@ void BrowsingHistoryHandler::HandleRemoveVisits(const base::ListValue* args) {
       &delete_task_tracker_);
 
   if (web_history) {
-    web_history_delete_request_ = web_history->ExpireHistory(
+    pending_delete_requests_++;

[Patrick Dubroy, 2014/02/20 12:56:55]

This seems to imply that there can be multiple deletions outstanding, which
shouldn't be the case. I think this should instead be a boolean, and the check
above should not allow a new deletion to begin while the web history deletion is
still outstanding.

[davidben, 2014/02/20 18:08:01]

Done.

+    web_history->ExpireHistory(
         expire_list,
         base::Bind(&BrowsingHistoryHandler::RemoveWebHistoryComplete,
-                   base::Unretained(this)));
+                   weak_factory_.GetWeakPtr()));
   }
 
 #if defined(ENABLE_EXTENSIONS)
@@ -886,14 +890,13 @@ void BrowsingHistoryHandler::RemoveComplete() {
 
   // Notify the page that the deletion request is complete, but only if a web
   // history delete request is not still pending.
-  if (!(web_history_delete_request_.get() &&
-        web_history_delete_request_->is_pending())) {
+  if (pending_delete_requests_ == 0) {
     web_ui()->CallJavascriptFunction("deleteComplete");
   }
 }
 
-void BrowsingHistoryHandler::RemoveWebHistoryComplete(
-    history::WebHistoryService::Request* request, bool success) {
+void BrowsingHistoryHandler::RemoveWebHistoryComplete(bool success) {
+  pending_delete_requests_--;
   // TODO(dubroy): Should we handle failure somehow? Delete directives will
   // ensure that the visits are eventually deleted, so maybe it's not necessary.
   if (!delete_task_tracker_.HasTrackedTasks())