Fixed memory leak in tests.

This patch fixes memory leak in BrowsingHistoryServiceTest tests
detected by ASAN build. Also changed TestingProfile to use already
implemented and correct(non leaking) version of
BlockUntilHistoryProcessesPendingRequests.
Leaking object was QuittingHistoryDBTask which is created and
passed to ScheduleDBTask function of HistoryService. To delete
this object HistoryBackend posts DeletePoiner task back to original
loop in ~QueuedHistoryDBTask. Yet nobody processes this task in
tests and its leakage is catched by ASAN.
history::BlockUntilHistoryProcessesPendingRequests in
history_service_test_util.cc calls HistoryService::FlushForTest
which does not create any objects in heap and is leak safe.

Change-Id: I76040ab9f52656d4c92b874d24ba0bc514e6a031
Reviewed-on: https://chromium-review.googlesource.com/789112
Commit-Queue: Alexander Yashkin <a-v-y@yandex-team.ru>
Reviewed-by: Brett Wilson <brettw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519592}

chrome/test/base/testing_profile.cc

@@ -65,8 +65,8 @@
 #include "components/history/core/browser/history_backend.h"
 #include "components/history/core/browser/history_constants.h"
 #include "components/history/core/browser/history_database_params.h"
-#include "components/history/core/browser/history_db_task.h"
 #include "components/history/core/browser/history_service.h"
+#include "components/history/core/test/history_service_test_util.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "components/keyed_service/core/refcounted_keyed_service.h"
 #include "components/offline_pages/features/features.h"
@@ -148,28 +148,6 @@ namespace {
 // Default profile name
 const char kTestingProfile[] = "testing_profile";
 
-// Task used to make sure history has finished processing a request. Intended
-// for use with BlockUntilHistoryProcessesPendingRequests.
-
-class QuittingHistoryDBTask : public history::HistoryDBTask {
- public:
-  QuittingHistoryDBTask() {}
-
-  bool RunOnDBThread(history::HistoryBackend* backend,
-                     history::HistoryDatabase* db) override {
-    return true;
-  }
-
-  void DoneRunOnMainThread() override {
-    base::RunLoop::QuitCurrentWhenIdleDeprecated();
-  }
-
- private:
-  ~QuittingHistoryDBTask() override {}
-
-  DISALLOW_COPY_AND_ASSIGN(QuittingHistoryDBTask);
-};
-
 class TestExtensionURLRequestContext : public net::URLRequestContext {
  public:
   TestExtensionURLRequestContext() {
@@ -925,13 +903,7 @@ void TestingProfile::BlockUntilHistoryProcessesPendingRequests() {
       HistoryServiceFactory::GetForProfile(this,
                                            ServiceAccessType::EXPLICIT_ACCESS);
   DCHECK(history_service);
-  DCHECK(base::MessageLoop::current());
-
-  base::CancelableTaskTracker tracker;
-  history_service->ScheduleDBTask(
-      std::unique_ptr<history::HistoryDBTask>(new QuittingHistoryDBTask()),
-      &tracker);
-  base::RunLoop().Run();
+  history::BlockUntilHistoryProcessesPendingRequests(history_service);
 }
 
 chrome_browser_net::Predictor* TestingProfile::GetNetworkPredictor() {

components/history/core/browser/browsing_history_service_unittest.cc

@@ -16,7 +16,6 @@
 #include "base/timer/mock_timer.h"
 #include "base/values.h"
 #include "components/history/core/browser/browsing_history_driver.h"
-#include "components/history/core/browser/history_db_task.h"
 #include "components/history/core/browser/history_service.h"
 #include "components/history/core/test/fake_web_history_service.h"
 #include "components/history/core/test/history_service_test_util.h"
@@ -57,23 +56,6 @@ struct TestResult {
 // Used to bind a callback.
 void DoNothing(bool ignored) {}
 
-class QuittingHistoryDBTask : public HistoryDBTask {
- public:
-  explicit QuittingHistoryDBTask(base::OnceClosure done_closure)
-      : done_closure_(std::move(done_closure)) {}
-
-  // HistoryDBTask implementation.
-  bool RunOnDBThread(history::HistoryBackend* backend,
-                     history::HistoryDatabase* db) override {
-    return true;
-  }
-  void DoneRunOnMainThread() override { std::move(done_closure_).Run(); }
-
- private:
-  base::OnceClosure done_closure_;
-  DISALLOW_COPY_AND_ASSIGN(QuittingHistoryDBTask);
-};
-
 class TestSyncService : public syncer::FakeSyncService {
  public:
   int GetObserverCount() { return observer_count_; }
@@ -232,12 +214,7 @@ class BrowsingHistoryServiceTest : public ::testing::Test {
   }
 
   void BlockUntilHistoryProcessesPendingRequests() {
-    base::CancelableTaskTracker tracker;
-    base::RunLoop run_loop;
-    local_history_->ScheduleDBTask(
-        std::make_unique<QuittingHistoryDBTask>(run_loop.QuitWhenIdleClosure()),
-        &tracker);
-    run_loop.Run();
+    history::BlockUntilHistoryProcessesPendingRequests(local_history());
   }
 
   Time OffsetToTime(int64_t hour_offset) {