Remove year+ old migration support of "session.urls_to_restore_on_startup".

components/syncable_prefs/pref_model_associator_unittest.cc

 // Copyright (c) 2011 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 "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/scoped_user_pref_update.h"
 #include "base/values.h"
 #include "components/syncable_prefs/pref_model_associator.h"
@@ skipping 18 matching lines @@
   // PrefModelAssociatorClient implementation.
   bool IsMergeableListPreference(const std::string& pref_name) const override {
     return pref_name == kListPrefName;
   }
 
   bool IsMergeableDictionaryPreference(
       const std::string& pref_name) const override {
     return pref_name == kDictionaryPrefName;
   }
 
-  bool IsMigratedPreference(const std::string& new_pref_name,
-                            std::string* old_pref_name) const override {
-    return false;
-  }
-
-  bool IsOldMigratedPreference(const std::string& old_pref_name,
-                               std::string* new_pref_name) const override {
-    return false;
-  }
-
  private:
   DISALLOW_COPY_AND_ASSIGN(TestPrefModelAssociatorClient);
 };
 
 class AbstractPreferenceMergeTest : public testing::Test {
  protected:
   AbstractPreferenceMergeTest() {
     PrefServiceMockFactory factory;
     factory.SetPrefModelAssociatorClient(&client_);
     scoped_refptr<user_prefs::PrefRegistrySyncable> pref_registry(
@@ skipping 408 matching lines @@
   base::DictionaryValue server_patterns_;
 };
 
 TEST_F(IndividualPreferenceMergeTest, ListPreference) {
   EXPECT_TRUE(MergeListPreference(kListPrefName));
 }
 
 }  // namespace
 
 }  // namespace syncable_prefs