-base.require('base.range');
-base.require('tracing.constants');
-base.require('tracing.selection');
-base.require('tracing.trace_model.slice');
+tvcm.require('tvcm.range');
+tvcm.require('tracing.constants');
+tvcm.require('tracing.selection');
+tvcm.require('tracing.trace_model.slice');
for (var i = 0; i < selection.length; i++) {
var event = selection[i];
var track = viewport.trackForEvent(event);
for (var i = 0; i < selection.length; i++) {
var event = selection[i];
var track = viewport.trackForEvent(event);