Remove remaining calls to deprecated MessageLoop methods on Mac.

chrome/browser/ui/cocoa/browser_window_controller_private.mm

Index: chrome/browser/ui/cocoa/browser_window_controller_private.mm
diff --git a/chrome/browser/ui/cocoa/browser_window_controller_private.mm b/chrome/browser/ui/cocoa/browser_window_controller_private.mm
index bc844c8e34b859f09f9302864bfeeef39da5e964..22505764c11a0f1aa08e91d4529dd056279a0674 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller_private.mm
+++ b/chrome/browser/ui/cocoa/browser_window_controller_private.mm
@@ -14,6 +14,7 @@
 #import "base/mac/scoped_nsobject.h"
 #import "base/mac/sdk_forward_declarations.h"
 #include "base/metrics/histogram.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/permissions/permission_request_manager.h"
 #include "chrome/browser/profiles/profile.h"
@@ -21,9 +22,9 @@
 #include "chrome/browser/ui/bookmarks/bookmark_tab_helper.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window_state.h"
+#import "chrome/browser/ui/cocoa/browser/exclusive_access_controller_views.h"
 #import "chrome/browser/ui/cocoa/browser_window_fullscreen_transition.h"
 #import "chrome/browser/ui/cocoa/browser_window_layout.h"
-#import "chrome/browser/ui/cocoa/browser/exclusive_access_controller_views.h"
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_sheet_controller.h"
 #import "chrome/browser/ui/cocoa/custom_frame_view.h"
 #import "chrome/browser/ui/cocoa/dev_tools_controller.h"
@@ -32,10 +33,10 @@
 #import "chrome/browser/ui/cocoa/floating_bar_backing_view.h"
 #import "chrome/browser/ui/cocoa/framed_browser_window.h"
 #include "chrome/browser/ui/cocoa/fullscreen_low_power_coordinator.h"
+#import "chrome/browser/ui/cocoa/fullscreen_toolbar_controller.h"
 #import "chrome/browser/ui/cocoa/fullscreen_window.h"
 #import "chrome/browser/ui/cocoa/infobars/infobar_container_controller.h"
 #include "chrome/browser/ui/cocoa/last_active_browser_cocoa.h"
-#import "chrome/browser/ui/cocoa/fullscreen_toolbar_controller.h"
 #import "chrome/browser/ui/cocoa/profiles/avatar_button_controller.h"
 #import "chrome/browser/ui/cocoa/profiles/avatar_icon_controller.h"
 #import "chrome/browser/ui/cocoa/status_bubble_mac.h"
@@ -745,7 +746,7 @@ willPositionSheet:(NSWindow*)sheet
 
         [[self window] setFrame:expectedFrame display:YES];
     });
-    base::MessageLoop::current()->PostTask(FROM_HERE, callback);
+    base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE, callback);
   }
 
   if (notification)  // For System Fullscreen when non-nil.