Not counting nested loops as time spent in a task

ui/views/win/hwnd_message_handler.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/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <oleacc.h>
 #include <shellapi.h>
 #include <wtsapi32.h>
 #pragma comment(lib, "wtsapi32.lib")
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
+#include "base/tracked_objects.h"
 #include "base/win/scoped_gdi_object.h"
 #include "base/win/win_util.h"
 #include "base/win/windows_version.h"
 #include "ui/base/touch/touch_enabled.h"
 #include "ui/base/view_prop.h"
 #include "ui/base/win/internal_constants.h"
 #include "ui/base/win/lock_state.h"
 #include "ui/base/win/mouse_wheel_util.h"
 #include "ui/base/win/shell.h"
 #include "ui/base/win/touch_input.h"
@@ skipping 2094 matching lines @@
     delegate_->HandleAccelerator(accelerator);
     return;
   }
 
   // If the delegate can't handle it, the system implementation will be called.
   if (!delegate_->HandleCommand(notification_code)) {
     // If the window is being resized by dragging the borders of the window
     // with the mouse/touch/keyboard, we flag as being in a size loop.
     if ((notification_code & sc_mask) == SC_SIZE)
       in_size_loop_ = true;
+    const bool runs_nested_loop = ((notification_code & sc_mask) == SC_SIZE) ||
+                                  ((notification_code & sc_mask) == SC_MOVE);
     base::WeakPtr<HWNDMessageHandler> ref(weak_factory_.GetWeakPtr());
+
+    // Use task stopwatch to exclude the time spend in the move/resize loop from
+    // the current task, if any.
+    tracked_objects::TaskStopwatch stopwatch;
+    if (runs_nested_loop)
+      stopwatch.Start();
     DefWindowProc(hwnd(), WM_SYSCOMMAND, notification_code,
                   MAKELPARAM(point.x(), point.y()));
+    if (runs_nested_loop)
+      stopwatch.Stop();
+
     if (!ref.get())
       return;
     in_size_loop_ = false;
   }
 }
 
 void HWNDMessageHandler::OnThemeChanged() {
   ui::NativeThemeWin::instance()->CloseHandles();
 }
 
@@ skipping 369 matching lines @@
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_HIDEWINDOW);
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_SHOWWINDOW);
   }
   // WM_DWMCOMPOSITIONCHANGED is only sent to top level windows, however we want
   // to notify our children too, since we can have MDI child windows who need to
   // update their appearance.
   EnumChildWindows(hwnd(), &SendDwmCompositionChanged, NULL);
 }
 
 }  // namespace views