Generalizing architecture for screenshot testing

chrome/browser/chromeos/login/screenshot_testing_mixin.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_TESTING_MIXIN_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENSHOT_TESTING_MIXIN_H_
+
+#include <string>
+
+#include "base/command_line.h"
+#include "base/timer/timer.h"
+#include "chrome/browser/chromeos/login/mixin_based_browser_test.h"
+#include "chrome/browser/chromeos/login/screenshot_tester.h"
+#include "content/public/test/browser_test_base.h"
+
+namespace chromeos {
+
+// Base mixin 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 ScreenshotTestingMixin : public MixinBasedBrowserTest::Mixin {
+ public:
+  ScreenshotTestingMixin();
+  virtual ~ScreenshotTestingMixin();
+
+  // Override from BrowsertestBase::Mixin.
+  virtual void SetUpInProcessBrowserTestFixture() OVERRIDE;
+
+  // Override from BrowsertestBase::Mixin.
+  virtual void SetUpCommandLine(base::CommandLine* command_line) OVERRIDE;
+
+  // Runs screenshot testing if it is turned on by command line switches.
+  void RunScreenshotTesting(const std::string& test_name);
+
+ private:
+  // 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();
+
+  // Required for current implementation of
+  // SynchronizeAnimationLoadWithCompositor()
+  base::OneShotTimer<ScreenshotTestingMixin> timer_;
+  base::Closure animation_waiter_quitter_;
+
+  // Is true if testing with screenshots is turned on with all proper switches.
+  bool enable_test_screenshots_;
+
+  // |screenshot_tester_ | does everything connected with taking, loading and
+  // comparing screenshots
+  ScreenshotTester screenshot_tester_;
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENSHOT_TESTING_MIXIN_H_