Make HistoryDBTask not refcounted, and ensure it's destroyed on its origin thread.

chrome/browser/history/history_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // History unit tests come in two flavors:
 //
 // 1. The more complicated style is that the unit test creates a full history
 //    service. This spawns a background thread for the history backend, and
 //    all communication is asynchronous. This is useful for testing more
 //    complicated things or end-to-end behavior.
@@ skipping 1484 matching lines @@
 
 // A HistoryDBTask implementation. Each time RunOnDBThread is invoked
 // invoke_count is increment. When invoked kWantInvokeCount times, true is
 // returned from RunOnDBThread which should stop RunOnDBThread from being
 // invoked again. When DoneRunOnMainThread is invoked, done_invoked is set to
 // true.
 class HistoryDBTaskImpl : public HistoryDBTask {
  public:
   static const int kWantInvokeCount;
 
-  HistoryDBTaskImpl() : invoke_count(0), done_invoked(false) {}
+  HistoryDBTaskImpl(int* invoke_count, bool* done_invoked)
+      : invoke_count_(invoke_count), done_invoked_(done_invoked) {}
 
   virtual bool RunOnDBThread(HistoryBackend* backend,
                              HistoryDatabase* db) OVERRIDE {
-    return (++invoke_count == kWantInvokeCount);
+    return (++*invoke_count_ == kWantInvokeCount);
   }
 
   virtual void DoneRunOnMainThread() OVERRIDE {
-    done_invoked = true;
+    *done_invoked_ = true;
     base::MessageLoop::current()->Quit();
   }
 
-  int invoke_count;
-  bool done_invoked;
+  int* invoke_count_;
+  bool* done_invoked_;
 
  private:
   virtual ~HistoryDBTaskImpl() {}
 
   DISALLOW_COPY_AND_ASSIGN(HistoryDBTaskImpl);
 };
 
 // static
 const int HistoryDBTaskImpl::kWantInvokeCount = 2;
 
 }  // namespace
 
 TEST_F(HistoryTest, HistoryDBTask) {
   ASSERT_TRUE(history_service_.get());
   base::CancelableTaskTracker task_tracker;
-  scoped_refptr<HistoryDBTaskImpl> task(new HistoryDBTaskImpl());
-  history_service_->ScheduleDBTask(task.get(), &task_tracker);
+  int invoke_count = 0;
+  bool done_invoked = false;
+  history_service_->ScheduleDBTask(
+      new HistoryDBTaskImpl(&invoke_count, &done_invoked), &task_tracker);
   // Run the message loop. When HistoryDBTaskImpl::DoneRunOnMainThread runs,
   // it will stop the message loop. If the test hangs here, it means
   // DoneRunOnMainThread isn't being invoked correctly.
   base::MessageLoop::current()->Run();
   CleanupHistoryService();
   // WARNING: history has now been deleted.
   history_service_.reset();
-  ASSERT_EQ(HistoryDBTaskImpl::kWantInvokeCount, task->invoke_count);
-  ASSERT_TRUE(task->done_invoked);
+  ASSERT_EQ(HistoryDBTaskImpl::kWantInvokeCount, invoke_count);
+  ASSERT_TRUE(done_invoked);
 }
 
 TEST_F(HistoryTest, HistoryDBTaskCanceled) {
   ASSERT_TRUE(history_service_.get());
   base::CancelableTaskTracker task_tracker;
-  scoped_refptr<HistoryDBTaskImpl> task(new HistoryDBTaskImpl());
-  history_service_->ScheduleDBTask(task.get(), &task_tracker);
+  int invoke_count = 0;
+  bool done_invoked = false;
+  history_service_->ScheduleDBTask(
+      new HistoryDBTaskImpl(&invoke_count, &done_invoked), &task_tracker);
   task_tracker.TryCancelAll();
   CleanupHistoryService();
   // WARNING: history has now been deleted.
   history_service_.reset();
-  ASSERT_FALSE(task->done_invoked);
+  ASSERT_FALSE(done_invoked);
 }
 
 // Create a local delete directive and process it while sync is
 // online, and then when offline. The delete directive should be sent to sync,
 // no error should be returned for the first time, and an error should be
 // returned for the second time.
 TEST_F(HistoryTest, ProcessLocalDeleteDirectiveSyncOnline) {
   ASSERT_TRUE(history_service_.get());
 
   const GURL test_url("http://www.google.com/");
@@ skipping 292 matching lines @@
   std::vector<PageUsageData*> results;
   db_->QuerySegmentUsage(segment_time, 10, &results);
   ASSERT_EQ(1u, results.size());
   EXPECT_EQ(url, results[0]->GetURL());
   EXPECT_EQ(segment_id, results[0]->GetID());
   EXPECT_EQ(title, results[0]->GetTitle());
   STLDeleteElements(&results);
 }
 
 }  // namespace history