[Sync] Replacing NULL with nullptr in code and null in comments for components/sync/

components/sync/driver/model_association_manager_unittest.cc

 // 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.
 
 #include "components/sync/driver/model_association_manager.h"
 
 #include "base/callback.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
@@ skipping 18 matching lines @@
                void(ModelType, const SyncError& error));
   MOCK_METHOD1(OnModelAssociationDone,
                void(const DataTypeManager::ConfigureResult& result));
 };
 
 FakeDataTypeController* GetController(
     const DataTypeController::TypeMap& controllers,
     ModelType model_type) {
   DataTypeController::TypeMap::const_iterator it = controllers.find(model_type);
   if (it == controllers.end()) {
-    return NULL;
+    return nullptr;
   }
   return static_cast<FakeDataTypeController*>(it->second.get());
 }
 
 ACTION_P(VerifyResult, expected_result) {
   EXPECT_EQ(arg0.status, expected_result.status);
   EXPECT_EQ(expected_result.requested_types, arg0.requested_types);
 }
 
 class SyncModelAssociationManagerTest : public testing::Test {
@@ skipping 413 matching lines @@
 
   EXPECT_CALL(delegate_, OnAllDataTypesReadyForConfigure());
   // Finish loading BOOKMARKS. This should trigger
   // OnAllDataTypesReadyForConfigure().
   GetController(controllers_, BOOKMARKS)->SimulateModelLoadFinishing();
   EXPECT_EQ(GetController(controllers_, BOOKMARKS)->state(),
             DataTypeController::MODEL_LOADED);
 }
 
 }  // namespace syncer