Revert of Stop passing raw pointers to base::Value API in c/b/chromeos and c/b/extensions

chrome/browser/extensions/api/preference/preference_api.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_PREFERENCE_PREFERENCE_API_H__
 #define CHROME_BROWSER_EXTENSIONS_API_PREFERENCE_PREFERENCE_API_H__
 
-#include <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/extensions/api/content_settings/content_settings_store.h"
 #include "chrome/browser/extensions/chrome_extension_function.h"
 #include "components/prefs/pref_change_registrar.h"
 #include "content/public/browser/notification_observer.h"
 #include "extensions/browser/browser_context_keyed_api_factory.h"
 #include "extensions/browser/event_router.h"
@@ skipping 126 matching lines @@
 class PrefTransformerInterface {
  public:
   virtual ~PrefTransformerInterface() {}
 
   // Converts the representation of a preference as seen by the extension
   // into a representation that is used in the pref stores of the browser.
   // Returns the pref store representation in case of success or sets
   // |error| and returns NULL otherwise. |bad_message| is passed to simulate
   // the behavior of EXTENSION_FUNCTION_VALIDATE. It is never NULL.
   // The ownership of the returned value is passed to the caller.
-  virtual std::unique_ptr<base::Value> ExtensionToBrowserPref(
+  virtual base::Value* ExtensionToBrowserPref(
       const base::Value* extension_pref,
       std::string* error,
       bool* bad_message) = 0;
 
   // Converts the representation of the preference as stored in the browser
   // into a representation that is used by the extension.
   // Returns the extension representation in case of success or NULL otherwise.
   // The ownership of the returned value is passed to the caller.
-  virtual std::unique_ptr<base::Value> BrowserToExtensionPref(
+  virtual base::Value* BrowserToExtensionPref(
       const base::Value* browser_pref) = 0;
 };
 
 // A base class to provide functionality common to the other *PreferenceFunction
 // classes.
 class PreferenceFunction : public UIThreadExtensionFunction {
  protected:
   enum PermissionType { PERMISSION_TYPE_READ, PERMISSION_TYPE_WRITE };
 
   ~PreferenceFunction() override;
@@ skipping 29 matching lines @@
  protected:
   ~ClearPreferenceFunction() override;
 
   // ExtensionFunction:
   ResponseAction Run() override;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_PREFERENCE_PREFERENCE_API_H__