arc: Fix race condition in applying modal state.

components/exo/shell_surface_unittest.cc

 // Copyright 2015 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 "components/exo/shell_surface.h"
 #include "ash/common/accessibility_delegate.h"
 #include "ash/common/wm/window_state.h"
 #include "ash/common/wm/wm_event.h"
 #include "ash/common/wm_shell.h"
 #include "ash/common/wm_window.h"
@@ skipping 453 matching lines @@
   EXPECT_FALSE(ash::WmShell::Get()->IsSystemModalWindowOpen());
 
   // Only SetSystemModal changes modality.
   shell_surface->SetSystemModal(true);
   EXPECT_TRUE(ash::WmShell::Get()->IsSystemModalWindowOpen());
 
   shell_surface->SetSystemModal(false);
   EXPECT_FALSE(ash::WmShell::Get()->IsSystemModalWindowOpen());
 }
 
+TEST_F(ShellSurfaceTest, ModalWindowSetSystemModalBeforeCommit) {
+  std::unique_ptr<Surface> surface(new Surface);
+  std::unique_ptr<ShellSurface> shell_surface(new ShellSurface(
+      surface.get(), nullptr, ShellSurface::BoundsMode::SHELL, gfx::Point(),
+      true, false, ash::kShellWindowId_SystemModalContainer));
+  gfx::Size desktop_size(640, 480);
+  std::unique_ptr<Buffer> desktop_buffer(
+      new Buffer(exo_test_helper()->CreateGpuMemoryBuffer(desktop_size)));
+  surface->Attach(desktop_buffer.get());
+  surface->SetInputRegion(SkRegion());
+
+  // Set SetSystemModal before any commit happens. Widget is not created at
+  // this time.
+  EXPECT_FALSE(shell_surface->GetWidget());
+  shell_surface->SetSystemModal(true);
+
+  surface->Commit();
+
+  // It is expected that modal window is shown.
+  EXPECT_TRUE(shell_surface->GetWidget());
+  EXPECT_TRUE(ash::WmShell::Get()->IsSystemModalWindowOpen());
+
+  // Now widget is created and setting modal state should be applied
+  // immediately.
+  shell_surface->SetSystemModal(false);
+  EXPECT_FALSE(ash::WmShell::Get()->IsSystemModalWindowOpen());
+}
+
 TEST_F(ShellSurfaceTest, PopupWindow) {
   Surface parent_surface;
   ShellSurface parent(&parent_surface);
   const gfx::Rect parent_bounds(100, 100, 300, 300);
 
   Buffer parent_buffer(
       exo_test_helper()->CreateGpuMemoryBuffer(parent_bounds.size()));
   parent_surface.Attach(&parent_buffer);
   parent_surface.Commit();
 
@@ skipping 460 matching lines @@
   shell_surface.OnAccessibilityModeChanged();
   shell_surface2.OnAccessibilityModeChanged();
 
   EXPECT_TRUE(shell_surface.shadow_underlay()->IsVisible());
   EXPECT_EQ(shadow_bounds, shell_surface.shadow_underlay()->bounds());
   EXPECT_EQ(shadow_bounds, shell_surface2.shadow_underlay()->bounds());
 }
 
 }  // namespace
 }  // namespace exo