Switch base::Value typemapping to be by value instead of by unique_ptr.

services/preferences/public/cpp/tracked/mock_validation_delegate.h

 // Copyright 2014 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 SERVICES_PREFERENCES_PUBLIC_CPP_TRACKED_MOCK_VALIDATION_DELEGATE_H_
 #define SERVICES_PREFERENCES_PUBLIC_CPP_TRACKED_MOCK_VALIDATION_DELEGATE_H_
 
 #include <stddef.h>
 
 #include <string>
@@ skipping 74 matching lines @@
 class MockValidationDelegate
     : public prefs::mojom::TrackedPreferenceValidationDelegate {
  public:
   explicit MockValidationDelegate(
       scoped_refptr<MockValidationDelegateRecord> record);
   ~MockValidationDelegate() override;
 
   // TrackedPreferenceValidationDelegate implementation.
   void OnAtomicPreferenceValidation(
       const std::string& pref_path,
-      std::unique_ptr<base::Value> value,
+      const base::Optional<base::Value>& value,
       prefs::mojom::TrackedPreferenceValidationDelegate::ValueState value_state,
       prefs::mojom::TrackedPreferenceValidationDelegate::ValueState
           external_validation_value_state,
       bool is_personal) override;
   void OnSplitPreferenceValidation(
       const std::string& pref_path,
       const std::vector<std::string>& invalid_keys,
       const std::vector<std::string>& external_validation_invalid_keys,
       prefs::mojom::TrackedPreferenceValidationDelegate::ValueState value_state,
       prefs::mojom::TrackedPreferenceValidationDelegate::ValueState
           external_validation_value_state,
       bool is_personal) override;
 
  private:
   // Adds a new validation event.
   void RecordValidation(
       const std::string& pref_path,
       prefs::mojom::TrackedPreferenceValidationDelegate::ValueState value_state,
       prefs::mojom::TrackedPreferenceValidationDelegate::ValueState
           external_validation_value_state,
       bool is_personal,
       prefs::mojom::TrackedPreferenceMetadata::PrefTrackingStrategy strategy);
 
   scoped_refptr<MockValidationDelegateRecord> record_;
 
   DISALLOW_COPY_AND_ASSIGN(MockValidationDelegate);
 };
 
 #endif  // SERVICES_PREFERENCES_PUBLIC_CPP_TRACKED_MOCK_VALIDATION_DELEGATE_H_