Added more useful message error message for plugin-types CSP directive.

Source/core/frame/csp/ContentSecurityPolicy.cpp

 /*
  * Copyright (C) 2011 Google, Inc. All rights reserved.
  *
  * 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 774 matching lines @@
 {
     String message = "Ignoring duplicate Content-Security-Policy directive '" + name + "'.\n";
     logToConsole(message);
 }
 
 void ContentSecurityPolicy::reportInvalidPluginTypes(const String& pluginType)
 {
     String message;
     if (pluginType.isNull())
         message = "'plugin-types' Content Security Policy directive is empty; all plugins will be blocked.\n";
+    else if (pluginType == "'none'")
+        message = "Invalid plugin type in 'plugin-types' Content Security Policy directive: '" + pluginType + "'. Did you mean to set the object-src directive to 'none'?\n";
     else
         message = "Invalid plugin type in 'plugin-types' Content Security Policy directive: '" + pluginType + "'.\n";
     logToConsole(message);
 }
 
 void ContentSecurityPolicy::reportInvalidSandboxFlags(const String& invalidFlags)
 {
     logToConsole("Error while parsing the 'sandbox' Content Security Policy directive: " + invalidFlags);
 }
 
@@ skipping 84 matching lines @@
     // Collisions have no security impact, so we can save space by storing only the string's hash rather than the whole report.
     return !m_violationReportsSent.contains(report.impl()->hash());
 }
 
 void ContentSecurityPolicy::didSendViolationReport(const String& report)
 {
     m_violationReportsSent.add(report.impl()->hash());
 }
 
 } // namespace blink