Add chrome.app.window API tests for items shown in shelf

chrome/browser/apps/app_browsertest_util.h

 // Copyright 2013 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_APPS_APP_BROWSERTEST_UTIL_H_
 #define CHROME_BROWSER_APPS_APP_BROWSERTEST_UTIL_H_
 
 #include <stddef.h>
 
 #include <string>
@@ skipping 106 matching lines @@
       const gfx::Rect& current_screen_bounds,
       const gfx::Size& minimum_size,
       gfx::Rect* bounds);
 
   // Load a simple test app and create a window. The window must be closed by
   // the caller in order to terminate the test - use CloseAppWindow().
   // |window_create_options| are the options that will be passed to
   // chrome.app.window.create() in the test app.
   AppWindow* CreateTestAppWindow(const std::string& window_create_options);
 
+  // Get the extension icon image for the app window.
+  const gfx::ImageSkia& GetAppIconImage(AppWindow* app_window);
+
  private:
 #if defined(OS_CHROMEOS)
   media_router::MockMediaRouter media_router_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(PlatformAppBrowserTest);
 };
 
 class ExperimentalPlatformAppBrowserTest : public PlatformAppBrowserTest {
  public:
   void SetUpCommandLine(base::CommandLine* command_line) override;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_APPS_APP_BROWSERTEST_UTIL_H_