Fix a copy-paste error in the extension activity log code

chrome/browser/extensions/activity_log/counting_policy.cc

 // Copyright 2013 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.
 
 // A policy for storing activity log data to a database that performs
 // aggregation to reduce the size of the database.  The database layout is
 // nearly the same as FullStreamUIPolicy, which stores a complete log, with a
 // few changes:
 //   - a "count" column is added to track how many log records were merged
 //     together into this row
@@ skipping 306 matching lines @@
     }
 
     // Assume there is an existing row for this action, and try to update the
     // count.
     sql::Statement update_statement(db->GetCachedStatement(
         sql::StatementID(SQL_FROM_HERE), update_str.c_str()));
     update_statement.BindInt64(0, action.time().ToInternalValue());
     update_statement.BindInt64(1, day_start.ToInternalValue());
     update_statement.BindInt64(2, next_day.ToInternalValue());
     for (size_t j = 0; j < matched_values.size(); j++) {
+      // A call to BindNull when matched_values contains -1 is likely not
+      // necessary as parameters default to null before they are explicitly
+      // bound.  But to be completely clear, and in case a cached statement
+      // ever comes with some values already bound, we bind all parameters
+      // (even null ones) explicitly.
       if (matched_values[j] == -1)
         update_statement.BindNull(j + 3);
       else
         update_statement.BindInt64(j + 3, matched_values[j]);
     }
     if (!update_statement.Run())
       return false;
 
     // Check if the update succeeded (was the count of updated rows non-zero)?
     // If it failed because no matching row existed, fall back to inserting a
     // new record.
     if (db->GetLastChangeCount() > 0) {
       if (db->GetLastChangeCount() > 1) {
         LOG(WARNING) << "Found and updated multiple rows in the activity log "
                      << "database; counts may be off!";
       }
       continue;
     }
     sql::Statement insert_statement(db->GetCachedStatement(
         sql::StatementID(SQL_FROM_HERE), insert_str.c_str()));
     insert_statement.BindInt64(0, action.time().ToInternalValue());
     for (size_t j = 0; j < matched_values.size(); j++) {
       if (matched_values[j] == -1)
-        update_statement.BindNull(j + 1);
+        insert_statement.BindNull(j + 1);
       else
         insert_statement.BindInt64(j + 1, matched_values[j]);
     }
     if (!insert_statement.Run())
       return false;
   }
 
   if (clean_database) {
     base::Time cutoff = (Now() - retention_time()).LocalMidnight();
     if (!CleanOlderThan(db, cutoff))
@@ skipping 135 matching lines @@
   return true;
 }
 
 void CountingPolicy::Close() {
   // The policy object should have never been created if there's no DB thread.
   DCHECK(BrowserThread::IsMessageLoopValid(BrowserThread::DB));
   ScheduleAndForget(activity_database(), &ActivityDatabase::Close);
 }
 
 }  // namespace extensions