React to primary display change instead of removal

chrome/browser/ui/webui/chromeos/login/oobe_display_chooser_browsertest.cc

+// Copyright 2017 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 "chrome/browser/ui/webui/chromeos/login/oobe_display_chooser.h"
+
+#include "ash/shell.h"
+#include "base/run_loop.h"
+#include "chrome/browser/chromeos/login/test/oobe_base_test.h"
+#include "chrome/browser/lifetime/application_lifetime.h"
+#include "chromeos/chromeos_switches.h"
+#include "ui/display/display.h"
+#include "ui/display/manager/display_manager.h"
+#include "ui/display/manager/managed_display_info.h"
+#include "ui/display/screen.h"
+#include "ui/display/test/display_manager_test_api.h"
+
+namespace chromeos {
+
+namespace {
+
+class OobeDisplayChooserTest : public OobeBaseTest {
+ public:
+  OobeDisplayChooserTest() {}
+  ~OobeDisplayChooserTest() override {}
+
+  void SetUpCommandLine(base::CommandLine* command_line) override {
+    command_line->AppendSwitch(switches::kOobeSkipPostLogin);
+
+    OobeBaseTest::SetUpCommandLine(command_line);
+  }
+
+  void TearDownOnMainThread() override {
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(&chrome::AttemptExit));

[oshima, 2017/05/23 14:45:39]

Do you know why you need this?

[Felix Ekblom, 2017/05/23 15:40:02]

No, and I don't strictly know _if_ I need it. It looked like something that
could make the tests behave more reliably so I copied it from the source of this
test class, OobeBaseTest, where it has existed from the start
(https://codereview.chromium.org/99863007).

My test still behave (and exit) nicely on a few try runs so I'll go ahead and
remove it.

+    content::RunMessageLoop();
+
+    OobeBaseTest::TearDownOnMainThread();
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(OobeDisplayChooserTest);
+};
+
+display::DisplayManager* display_manager() {
+  return ash::Shell::Get()->display_manager();
+}
+
+int64_t GetPrimaryDisplay() {
+  return display::Screen::GetScreen()->GetPrimaryDisplay().id();
+}
+
+}  // namespace
+
+// Test that display removal does not trigger CHECK in
+// WindowTreeHostManager::GetPrimaryDisplayId().
+IN_PROC_BROWSER_TEST_F(OobeDisplayChooserTest,
+                       RemovingPrimaryDisplaySanityCheck) {
+  display::ManagedDisplayInfo info1(1, "x-1", false);
+  info1.SetBounds(gfx::Rect(0, 0, 1280, 800));
+  display::ManagedDisplayInfo info2(2, "x-2", false);
+  std::vector<display::ManagedDisplayInfo> info_list;
+  info2.SetBounds(gfx::Rect(0, 1280, 1280, 800));
+  info_list.push_back(info1);
+  info_list.push_back(info2);
+
+  display_manager()->OnNativeDisplaysChanged(info_list);
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(1, GetPrimaryDisplay());
+
+  info_list.erase(info_list.begin());
+  display_manager()->OnNativeDisplaysChanged(info_list);
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(2, GetPrimaryDisplay());
+}
+
+}  // namespace chromeos