Not counting nested loops as time spent in a task

ui/views/widget/desktop_aura/desktop_drag_drop_client_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/widget/desktop_aura/desktop_drag_drop_client_win.h"
 
+#include "base/tracked_objects.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/base/dragdrop/drag_source_win.h"
 #include "ui/base/dragdrop/drop_target_event.h"
 #include "ui/base/dragdrop/os_exchange_data_provider_win.h"
 #include "ui/views/widget/desktop_aura/desktop_drop_target_win.h"
 #include "ui/views/widget/desktop_aura/desktop_window_tree_host_win.h"
 
 namespace views {
 
 DesktopDragDropClientWin::DesktopDragDropClientWin(
@@ skipping 12 matching lines @@
     aura::Window* root_window,
     aura::Window* source_window,
     const gfx::Point& root_location,
     int operation,
     ui::DragDropTypes::DragEventSource source) {
   drag_drop_in_progress_ = true;
   drag_operation_ = operation;
 
   drag_source_ = new ui::DragSourceWin;
   DWORD effect;
+
+  // Use task stopwatch to exclude the drag-drop time current task, if any.
+  tracked_objects::TaskStopwatch stopwatch;
+  stopwatch.Start();
   HRESULT result = DoDragDrop(
       ui::OSExchangeDataProviderWin::GetIDataObject(data), drag_source_.get(),
       ui::DragDropTypes::DragOperationToDropEffect(operation), &effect);
+  stopwatch.Stop();
 
   drag_drop_in_progress_ = false;
 
   if (result != DRAGDROP_S_DROP)
     effect = DROPEFFECT_NONE;
 
   return ui::DragDropTypes::DropEffectToDragOperation(effect);
 }
 
 void DesktopDragDropClientWin::DragUpdate(aura::Window* target,
@@ skipping 14 matching lines @@
 }
 
 void DesktopDragDropClientWin::OnNativeWidgetDestroying(HWND window) {
   if (drop_target_.get()) {
     RevokeDragDrop(window);
     drop_target_ = NULL;
   }
 }
 
 }  // namespace views