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

chrome/chrome_browser_ui.gypi

Index: chrome/chrome_browser_ui.gypi
diff --git a/chrome/chrome_browser_ui.gypi b/chrome/chrome_browser_ui.gypi
index efcb10934f0442c623ce298aa2f9007e76d212f1..daecd2435c9081c2fcf8eb74365f3a5e4c868dfd 100644
--- a/chrome/chrome_browser_ui.gypi
+++ b/chrome/chrome_browser_ui.gypi
@@ -2684,6 +2684,10 @@
       'browser/ui/webui/policy_ui.h',
     ],
     'chrome_browser_ui_print_preview_sources': [
+      'browser/ui/webui/print_preview/hidden_print_preview.cc',
+      'browser/ui/webui/print_preview/hidden_print_preview.h',
+      'browser/ui/webui/print_preview/hidden_web_contents.cc',
+      'browser/ui/webui/print_preview/hidden_web_contents.h',
       'browser/ui/webui/print_preview/extension_printer_handler.cc',
       'browser/ui/webui/print_preview/extension_printer_handler.h',
       'browser/ui/webui/print_preview/print_preview_handler.cc',