Add a "Simplify Page" option to the print preview dialog

chrome/chrome_tests_unit.gypi

 # Copyright 2012 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.
 {
   'variables': {
     'chrome_unit_tests_sources': [
       '../components/autofill/content/renderer/test_password_autofill_agent.cc',
       '../components/autofill/content/renderer/test_password_autofill_agent.h',
       '../components/autofill/content/renderer/test_password_generation_agent.cc',
       '../components/autofill/content/renderer/test_password_generation_agent.h',
@@ skipping 1064 matching lines @@
       'common/pepper_permission_util_unittest.cc',
     ],
     'chrome_unit_tests_print_preview_sources': [
       'browser/printing/cloud_print/cloud_print_proxy_service_unittest.cc',
       'browser/printing/print_dialog_cloud_unittest.cc',
       'browser/printing/print_job_unittest.cc',
       'browser/printing/print_preview_dialog_controller_unittest.cc',
       'browser/printing/print_preview_test.cc',
       'browser/printing/print_preview_test.h',
       'browser/ui/webui/print_preview/extension_printer_handler_unittest.cc',
+      'browser/ui/webui/print_preview/hidden_web_contents_unittest.cc',
       'browser/ui/webui/print_preview/print_preview_ui_unittest.cc',
       'common/service_process_util_unittest.cc',
       'service/cloud_print/cloud_print_service_helpers_unittest.cc',
       'service/cloud_print/cloud_print_token_store_unittest.cc',
       'service/cloud_print/cloud_print_url_fetcher_unittest.cc',
       'service/cloud_print/connector_settings_unittest.cc',
       'service/cloud_print/printer_job_handler_unittest.cc',
       'service/cloud_print/printer_job_queue_handler_unittest.cc',
       'service/service_process_prefs_unittest.cc',
       'service/service_process_unittest.cc',
@@ skipping 1681 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }