Not counting nested loops as time spent in a task.

While in a nested loop, Chrome is not blocked, keeps updating the client area and is responding to user actions.
Subtracting the time in nested loops from the task in which it happens, so that we don't diagnose this task as a source of jank.

BUG=401560, 440919

Review URL: https://codereview.chromium.org/788883004

Cr-Commit-Position: refs/heads/master@{#308218}

ui/gfx/win/hwnd_util.cc

@@ -6,6 +6,7 @@
 
 #include "base/i18n/rtl.h"
 #include "base/strings/string_util.h"
+#include "base/tracked_objects.h"
 #include "base/win/metro.h"
 #include "base/win/win_util.h"
 #include "ui/gfx/point.h"
@@ -222,8 +223,15 @@ void ShowSystemMenuAtPoint(HWND window, const Point& point) {
   if (base::i18n::IsRTL())
     flags |= TPM_RIGHTALIGN;
   HMENU menu = GetSystemMenu(window, FALSE);
+
+  // Use task stopwatch to exclude the time while the context menu is open from
+  // the current task, if any.
+  tracked_objects::TaskStopwatch stopwatch;
+  stopwatch.Start();
   const int command =
       TrackPopupMenu(menu, flags, point.x(), point.y(), 0, window, NULL);
+  stopwatch.Stop();
+
   if (command)
     SendMessage(window, WM_SYSCOMMAND, command, 0);
 }

ui/views/widget/desktop_aura/desktop_drag_drop_client_win.cc

@@ -4,6 +4,7 @@
 
 #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"
@@ -36,9 +37,14 @@ int DesktopDragDropClientWin::StartDragAndDrop(
 
   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;
 

ui/views/win/hwnd_message_handler.cc

@@ -12,6 +12,7 @@
 
 #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"
@@ -2126,9 +2127,20 @@ void HWNDMessageHandler::OnSysCommand(UINT notification_code,
     // 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;