Adding a SQL implementation of the backing store for previews opt outs

components/previews/core/previews_io_data_unittest.cc

 // Copyright 2016 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.
 
 #include "components/previews/core/previews_io_data.h"
 
 #include <memory>
 
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
@@ skipping 13 matching lines @@
       const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner,
       const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner)
       : PreviewsIOData(io_task_runner, ui_task_runner), initialized_(false) {}
   ~TestPreviewsIOData() override {}
 
   // Whether Initialize was called.
   bool initialized() { return initialized_; }
 
  private:
   // Set |initialized_| to true and use base class functionality.
-  void InitializeOnIOThread(
-      std::unique_ptr<PreviewsOptOutStore> previews_opt_out_store) override {
+  void InitializeOnIOThread() override {
     initialized_ = true;
-    PreviewsIOData::InitializeOnIOThread(std::move(previews_opt_out_store));
+    PreviewsIOData::InitializeOnIOThread();
   }
 
   // Whether Initialize was called.
   bool initialized_;
 };
 
 class PreviewsIODataTest : public testing::Test {
  public:
   PreviewsIODataTest() {}
 
@@ skipping 25 matching lines @@
       new TestPreviewsIOData(loop_.task_runner(), loop_.task_runner())));
   set_ui_service(base::WrapUnique(
       new PreviewsUIService(io_data(), loop_.task_runner(), nullptr)));
   base::RunLoop().RunUntilIdle();
   // After the outstanding posted tasks have run, |io_data_| should be fully
   // initialized.
   EXPECT_TRUE(io_data()->initialized());
 }
 
 }  // namespace previews