Move the Mac Task Manager to the new backend code.

chrome/browser/task_management/task_manager_tester.h

Index: chrome/browser/task_management/task_manager_tester.h
diff --git a/chrome/browser/task_management/task_manager_tester.h b/chrome/browser/task_management/task_manager_tester.h
index be9964724615b57927e75198d47d42a30834ebff..bc0297eccf6b1fa0290d6cf9b6e0634f8a3511cc 100644
--- a/chrome/browser/task_management/task_manager_tester.h
+++ b/chrome/browser/task_management/task_manager_tester.h
@@ -15,7 +15,7 @@
 
 namespace task_management {
 
-// An adapter that abstracts away the difference of old vs. new task manager.
+// An adapter to simplify testing the task manager.
 class TaskManagerTester {
  public:
   using ColumnSpecifier = browsertest_util::ColumnSpecifier;
@@ -26,9 +26,6 @@ class TaskManagerTester {
   static std::unique_ptr<TaskManagerTester> Create(
       const base::Closure& callback);
 
-  // If using a legacy task manager, refresh the model.
-  static void MaybeRefreshLegacyInstance();
-
   virtual ~TaskManagerTester() {}
 
   // Get the number of rows currently in the task manager.
@@ -54,11 +51,6 @@ class TaskManagerTester {
   // Gets the start index and length of the group to which the task at
   // |row_index| belongs.
   virtual void GetRowsGroupRange(int row, int* out_start, int* out_length) = 0;
-
- private:
-  // Always creates a tester for the non-legacy TaskManager.
-  static std::unique_ptr<TaskManagerTester> CreateDefault(
-      const base::Closure& callback);
 };
 
 }  // namespace task_management