Fix task manager table scrollbar issue.

chrome/browser/ui/task_manager/task_manager_table_model.cc

Index: chrome/browser/ui/task_manager/task_manager_table_model.cc
diff --git a/chrome/browser/ui/task_manager/task_manager_table_model.cc b/chrome/browser/ui/task_manager/task_manager_table_model.cc
index 3ee0752505b55baa52550a3c4b43303d0f4a87d9..c030f71ae4dc65380f0c1b8d5712bb2ce5dd2c54 100644
--- a/chrome/browser/ui/task_manager/task_manager_table_model.cc
+++ b/chrome/browser/ui/task_manager/task_manager_table_model.cc
@@ -584,6 +584,13 @@ void TaskManagerTableModel::StartUpdating() {
   TaskManagerInterface::GetTaskManager()->AddObserver(this);
   tasks_ = observed_task_manager()->GetTaskIdsList();
   OnRefresh();
+
+  // In order for the scrollbar of the TableView to work properly on startup of
+  // the task manager, we must invoke TableModelObserver::OnModelChanged() which
+  // in turn will invoke TableView::NumRowsChanged(). This will adjust the
+  // vertical scrollbar correctly. crbug.com/570966.
+  if (table_model_observer_)
+    table_model_observer_->OnModelChanged();
 }
 
 void TaskManagerTableModel::StopUpdating() {