HistoryQuickProviderTest.DeleteMatch thread safety fix.

components/history/core/browser/history_service.cc

Index: components/history/core/browser/history_service.cc
diff --git a/components/history/core/browser/history_service.cc b/components/history/core/browser/history_service.cc
index c0e953608e06c0821968275cbeb161878070917c..01f75d288be525e47cec6934aaf71d6ff9813031 100644
--- a/components/history/core/browser/history_service.cc
+++ b/components/history/core/browser/history_service.cc
@@ -345,8 +345,12 @@ base::CancelableTaskTracker::TaskId HistoryService::ScheduleDBTask(
 }
 
 void HistoryService::FlushForTest(const base::Closure& flushed) {
-  after_startup_task_runner_->PostTaskAndReply(
-      FROM_HERE, base::Bind(&base::DoNothing), flushed);
+  PostTaskAndReplyForTest(base::Bind(&base::DoNothing), flushed);
+}
+
+bool HistoryService::PostTaskAndReplyForTest(const base::Closure& task,
+                                             const base::Closure& reply) {
+  return after_startup_task_runner_->PostTaskAndReply(FROM_HERE, task, reply);
 }
 
 void HistoryService::SetOnBackendDestroyTask(const base::Closure& task) {