Add a TestBrowserDialog helper class for testing browser dialogs in a consistent way.

chrome/browser/ui/test/test_browser_dialog.cc

+// Copyright 2016 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/test/test_browser_dialog.h"
+
+#include "base/command_line.h"
+#include "base/message_loop/message_loop.h"
+#include "chrome/browser/platform_util.h"
+#include "ui/base/material_design/material_design_controller.h"
+#include "ui/base/test/material_design_controller_test_api.h"
+#include "ui/base/test/user_interactive_test_case.h"
+#include "ui/base/ui_base_switches.h"
+#include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_observer.h"
+
+namespace {
+
+// An automatic action for WidgetCloser to post to the RunLoop.
+// TODO(tapted): Explore asynchronous Widget::Close() and DialogClientView::
+// {Accept,Cancel}Window() approaches to test other dialog lifetimes.
+enum class DialogAction {
+  INTERACTIVE,  // Run interactively.
+  CLOSE_NOW,    // Call Widget::CloseNow().
+};
+
+// Helper to break out of the nested run loop that runs a test dialog.
+class WidgetCloser : public views::WidgetObserver {
+ public:
+  WidgetCloser(views::Widget* widget, DialogAction action)
+      : widget_(widget), weak_ptr_factory_(this) {
+    widget->AddObserver(this);
+    if (action == DialogAction::INTERACTIVE)
+      return;
+
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE,
+        base::Bind(&WidgetCloser::CloseNow, weak_ptr_factory_.GetWeakPtr()));
+  }
+
+  // WidgetObserver:
+  void OnWidgetDestroyed(views::Widget* widget) override {
+    widget_->RemoveObserver(this);
+    widget_ = nullptr;
+    base::MessageLoop::current()->QuitNow();
+  }
+
+ private:
+  void CloseNow() {
+    if (widget_)
+      widget_->CloseNow();
+  }
+
+  views::Widget* widget_;
+
+  base::WeakPtrFactory<WidgetCloser> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(WidgetCloser);
+};
+
+// Extracts the |name| argument for ShowDialog() from the current test case.
+std::string NameFromTestCase() {

[Paweł Hajdan Jr., 2016/12/20 16:27:15]

Is this the same as TestNameWithoutDisabledPrefix from base/test/gtest_util.h?

[tapted, 2016/12/20 23:34:47]

Thanks for the pointer - there's some interesting stuff there. This is
effectively `gsed -r 's/^(DISABLED_)?[^_]*_//'`, so a bit different. Added an
example comment to the CL:

// E.g. for InvokeDialog_name (or DISABLED_InvokeDialog_name) returns "name".

But we can use TestNameWithoutDisabledPrefix for a bit of cleanup [Done.].

+  const std::string disabled_prefix = "DISABLED_";
+  std::string name =
+      testing::UnitTest::GetInstance()->current_test_info()->name();
+  if (name.find(disabled_prefix) == 0)
+    name = name.substr(disabled_prefix.size());
+
+  std::string::size_type underscore = name.find('_');
+  return underscore == std::string::npos ? std::string()
+                                         : name.substr(underscore + 1);
+}
+
+}  // namespace
+
+TestBrowserDialog::TestBrowserDialog() {}
+
+void TestBrowserDialog::RunDialog() {
+#if defined(OS_MACOSX)
+  // The rest of this method assumes the child dialog is toolkit-views. So, for
+  // Mac, it will only work if --secondary-ui-md is passed. Without this, a
+  // Cocoa dialog will be created, which TestBrowserDialog doesn't support.
+  // Force SecondaryUiMaterial() on Mac to get coverage on the bots. Leave it
+  // optional elsewhere so that the non-MD dialog can be invoked to compare.
+  ui::test::MaterialDesignControllerTestAPI md_test_api(
+      ui::MaterialDesignController::GetMode());
+  md_test_api.SetSecondaryUiMaterial(true);
+#endif
+
+  gfx::NativeView parent = platform_util::GetViewForWindow(DialogParent());
+  views::Widget::Widgets widgets_before;
+  views::Widget::GetAllChildWidgets(parent, &widgets_before);
+
+  ShowDialog(NameFromTestCase());
+  views::Widget::Widgets widgets_after;
+  views::Widget::GetAllChildWidgets(parent, &widgets_after);
+
+  auto added = base::STLSetDifference<std::vector<views::Widget*>>(
+      widgets_after, widgets_before);
+
+  // This can fail if no dialog was shown, if the dialog shown wasn't a toolkit-
+  // views dialog, or if more than one child dialog was shown.
+  ASSERT_EQ(1u, added.size());
+
+  const DialogAction action = base::CommandLine::ForCurrentProcess()->HasSwitch(
+                                  internal::kInteractiveSwitch)
+                                  ? DialogAction::INTERACTIVE
+                                  : DialogAction::CLOSE_NOW;
+
+  WidgetCloser closer(added[0], action);
+  ::test::RunTestInteractively();
+}