Generalizing architecture for screenshot testing

chrome/browser/chromeos/login/screenshot_test.h

+// Copyright 2014 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_LOGIN_SCREENSHOT_TEST_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENSHOT_TEST_H_
+
+#include <string>
+
+#include "base/command_line.h"
+#include "base/timer/timer.h"
+#include "chrome/browser/chromeos/login/login_manager_test.h"
+#include "chrome/browser/chromeos/login/screenshot_tester.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+
+namespace chromeos {
+
+// Base class for tests which support testing with screenshots.
+// Sets up everything required for taking screenshots.
+// Provides functionality to deal with animation load: screenshots
+// should be taken only when all the animation is loaded.
+class ScreenshotTest : public LoginManagerTest,

[dzhioev (left Google), 2014/08/07 11:23:55]

Can't we derieve LoginManagerTest from ScreenshotTest instead?

+                       public content::NotificationObserver {
+ public:
+  ScreenshotTest();
+  virtual ~ScreenshotTest();
+
+  // Override from LoginManagerTest.
+  virtual void SetUpOnMainThread() OVERRIDE;
+
+  // Override from LoginManagerTest.
+  virtual void SetUpCommandLine(base::CommandLine* command_line) OVERRIDE;
+
+  // Override from content::NotificationObserver.
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
+  // This method checks if animation is loaded, and, if not,
+  // waits until it is loaded and properly shown on the screen.
+  void WaitUntilAnimationLoads();
+
+ protected:
+  // Does all the required initializations for properly handling
+  // animation-connected issues.
+  // Should be overriden for each test according to which exactly animation
+  // exists in it.
+  virtual void InitializeAnimationHandler();
+
+  // Runs screenshot testing if it is turned on by command line switches.
+  void RunScreenshotTesting(const std::string& test_name);
+
+  // Returns true if, according to the notificatons received, animation has
+  // finished loading by now.
+  // Should be overriden for each test according to which exactly animation
+  // exists in it.
+  virtual bool IsAnimationLoaded();
+
+  bool waiter_loop_is_on_;
+  base::Closure animation_waiter_quitter_;
+  content::NotificationRegistrar registrar_;
+
+ private:
+  // Does all the required initializations before waiting for animation.
+  void PrepareForAnimationWaiting(const base::Closure& quitter);
+
+  // It turns out that it takes some more time for the animation
+  // to finish loading even after all the notifications have been sent.
+  // That happens due to some properties of compositor.
+  // This method should be used after getting all the necessary notifications
+  // to wait for the actual load of animation.
+  void SynchronizeAnimationLoadWithCompositor();
+
+  // This method exists only because of the current implementation of
+  // SynchronizeAnimationLoadWithCompositor.
+  void HandleAnimationLoad();
+
+  base::OneShotTimer<ScreenshotTest> timer_;
+
+  // Is true if testing with screenshots is turned on with all proper switches.
+  bool enable_test_screenshots_;
+
+  ScreenshotTester screenshot_tester;

[dzhioev (left Google), 2014/08/07 11:23:55]

screenshot_tester_

+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENSHOT_TEST_H_