MacViews: Consolidate flags. Just use --secondary-ui-md to enable MacViews.

chrome/browser/ui/views/browser_dialogs_views_mac.cc

Index: chrome/browser/ui/views/browser_dialogs_views_mac.cc
diff --git a/chrome/browser/ui/views/browser_dialogs_views_mac.cc b/chrome/browser/ui/views/browser_dialogs_views_mac.cc
index 4ba50ba7d88cd19711e175ca66af529fe5ff406f..276b2fa0eccc2ddf22b3758b1b56ba43109287e8 100644
--- a/chrome/browser/ui/views/browser_dialogs_views_mac.cc
+++ b/chrome/browser/ui/views/browser_dialogs_views_mac.cc
@@ -59,9 +59,6 @@ void ShowBookmarkBubbleViewsAtPoint(const gfx::Point& anchor_point,
 }
 
 task_manager::TaskManagerTableModel* ShowTaskManagerViews(Browser* browser) {
-  // On platforms other than Mac, the Views task manager is shown unless
-  // explicitly disabled. Assume that running with ToolkitViewsDialogsEnabled()
-  // on Mac also means the Views task manager is desired.

[tapted, 2016/11/28 07:45:51]

(this comment became obsolete in r409593 "The "new" Views Task Manager is the
only one." but is was reworded instead -- s/new/Views/)

   return task_manager::TaskManagerView::Show(browser);
 }