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

components/sync/engine_impl/directory_update_handler_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/engine_impl/directory_update_handler.h"
 
 #include <stdint.h>
 
 #include <set>
 #include <string>
@@ skipping 718 matching lines @@
 
     // Re-parent from root to "Y"
     entry.PutServerVersion(entry_factory()->GetNextRevision());
     entry.PutIsUnappliedUpdate(true);
     entry.PutServerParentId(TestIdFactory::MakeServer("Y"));
   }
 
   // Item 'Y' is child of 'X'.
   entry_factory()->CreateUnsyncedItem(TestIdFactory::MakeServer("Y"),
                                       TestIdFactory::MakeServer("X"), "Y", true,
-                                      BOOKMARKS, NULL);
+                                      BOOKMARKS, nullptr);
 
   // If the server's update were applied, we would have X be a child of Y, and Y
   // as a child of X.  That's a directory loop.  The UpdateApplicator should
   // prevent the update from being applied and note that this is a hierarchy
   // conflict.
 
   StatusController status;
   ApplyBookmarkUpdates(&status);
 
   // This should count as a hierarchy conflict.
@@ skipping 62 matching lines @@
     // Delete it on the server.
     entry.PutServerVersion(entry_factory()->GetNextRevision());
     entry.PutIsUnappliedUpdate(true);
     entry.PutServerParentId(TestIdFactory::root());
     entry.PutServerIsDel(true);
   }
 
   // Create a local child of the server-deleted directory.
   entry_factory()->CreateUnsyncedItem(TestIdFactory::MakeServer("child"),
                                       TestIdFactory::MakeServer("parent"),
-                                      "child", false, BOOKMARKS, NULL);
+                                      "child", false, BOOKMARKS, nullptr);
 
   // The server's request to delete the directory must be ignored, otherwise our
   // unsynced new child would be orphaned.  This is a hierarchy conflict.
 
   StatusController status;
   ApplyBookmarkUpdates(&status);
 
   // This should count as a hierarchy conflict.
   const UpdateCounters& counters = GetBookmarksUpdateCounters();
   EXPECT_EQ(1, counters.num_hierarchy_conflict_application_failures);
@@ skipping 320 matching lines @@
   const UpdateCounters& counters = GetArticlesUpdateCounters();
   EXPECT_EQ(1, counters.num_updates_applied);
   EXPECT_EQ(1, counters.num_local_overwrites);
   EXPECT_EQ(0, counters.num_server_overwrites);
   local_metadata = entry_factory()->GetLocalAttachmentMetadataForItem(handle);
   EXPECT_EQ(server_metadata.SerializeAsString(),
             local_metadata.SerializeAsString());
 }
 
 }  // namespace syncer