Enable WidgetTestInteractive.DesktopNativeWidgetWithModalTransientChild on OS_WIN

ui/views/widget/widget_interactive_uitest.cc

 // Copyright (c) 2013 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 <stddef.h>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/macros.h"
@@ skipping 1253 matching lines @@
   EXPECT_TRUE(minimize_waiter.Wait());
 
   PropertyWaiter restore_waiter(
       base::Bind(&Widget::IsMinimized, base::Unretained(widget)), false);
   widget->Restore();
   EXPECT_TRUE(restore_waiter.Wait());
 
   widget->CloseNow();
 }
 
-#if defined(OS_LINUX) && !defined(OS_CHROMEOS) && !defined(OS_WIN)
-// TODO(warx): Investigate the flakiness on OS_WIN (crbug.com/729331).
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
 // Tests that when a desktop native widget has modal transient child, it should
 // avoid restore focused view itself as the modal transient child window will do
 // that, thus avoids having multiple focused view visually (crbug.com/727641).
 TEST_F(WidgetTestInteractive, DesktopNativeWidgetWithModalTransientChild) {
+#if defined(OS_WIN)

[sky, 2017/06/07 16:09:34]

I get that you really only need this for windows, but will it matter on other
platforms? Can you always do it?

[Qiang(Joe) Xu, 2017/06/07 17:28:17]

yes, we can always do it. Done.

+  // On Windows, Widget::Deactivate() works by activating the next topmost
+  // window on the z-order stack. This only works if there is at least one other
+  // window, so make sure that is the case.
+  Widget* deactivate_widget = CreateWidget();
+  deactivate_widget->Show();
+#endif
   // Create a top level desktop native widget.
   Widget* top_level = CreateWidget();
 
   Textfield* textfield = new Textfield;
   textfield->SetBounds(0, 0, 200, 20);
   top_level->GetRootView()->AddChildView(textfield);
   ShowSync(top_level);
   textfield->RequestFocus();
   EXPECT_TRUE(textfield->HasFocus());
 
@@ skipping 18 matching lines @@
   EXPECT_FALSE(dialog_textfield->HasFocus());
   EXPECT_FALSE(textfield->HasFocus());
 
   // After deactivation and activation of top level widget, only modal dialog
   // should restore focused view.
   ActivateSync(top_level);
   EXPECT_TRUE(dialog_textfield->HasFocus());
   EXPECT_FALSE(textfield->HasFocus());
 
   top_level->CloseNow();
+
+#if defined(OS_WIN)
+  deactivate_widget->CloseNow();
+#endif
 }
-#endif  // defined(USE_AURA) && !defined(OS_CHROMEOS) && !defined(OS_WIN)
+#endif  // defined(USE_AURA) && !defined(OS_CHROMEOS)
 
 namespace {
 
 // Helper class for CaptureLostTrackingWidget to store whether
 // OnMouseCaptureLost has been invoked for a widget.
 class CaptureLostState {
  public:
   CaptureLostState() : got_capture_lost_(false) {}
 
   bool GetAndClearGotCaptureLost() {
@@ skipping 580 matching lines @@
 
   ui::KeyEvent key_event2(key_event);
   widget->OnKeyEvent(&key_event2);
   EXPECT_FALSE(key_event2.stopped_propagation());
 
   widget->CloseNow();
 }
 
 }  // namespace test
 }  // namespace views