Sandbox should prevent 'execCommand("print", ...)'.

third_party/WebKit/Source/core/editing/commands/EditorCommand.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Igalia S.L.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 1520 matching lines @@
   return true;
 }
 
 static bool executePrint(LocalFrame& frame,
                          Event*,
                          EditorCommandSource,
                          const String&) {
   FrameHost* host = frame.host();
   if (!host)
     return false;
-  host->chromeClient().print(&frame);
-  return true;
+  return host->chromeClient().print(&frame);
 }
 
 static bool executeRedo(LocalFrame& frame,
                         Event*,
                         EditorCommandSource,
                         const String&) {
   frame.editor().redo();
   return true;
 }
 
@@ skipping 1183 matching lines @@
           *m_frame, DirectionBackward, WordGranularity);
     case WebEditingCommandType::DeleteWordForward:
       return RangesFromCurrentSelectionOrExtendCaret(*m_frame, DirectionForward,
                                                      WordGranularity);
     default:
       return nullptr;
   }
 }
 
 }  // namespace blink