Fix plugins' mixed content status.

Source/core/loader/MixedContentChecker.cpp

 /*
  * Copyright (C) 2012 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
@@ skipping 94 matching lines @@
     // "Optionally-blockable" mixed content
     case WebURLRequest::RequestContextAudio:
     case WebURLRequest::RequestContextFavicon:
     case WebURLRequest::RequestContextImage:
     case WebURLRequest::RequestContextVideo:
         return ContextTypeOptionallyBlockable;
 
     // Plugins! Oh how dearly we love plugin-loaded content!
     case WebURLRequest::RequestContextPlugin: {
         Settings* settings = frame->settings();
-        return settings || settings->strictMixedContentCheckingForPlugin() ? ContextTypeBlockable : ContextTypeOptionallyBlockable;
+        return settings && settings->strictMixedContentCheckingForPlugin() ? ContextTypeBlockable : ContextTypeOptionallyBlockable;
     }
 
     // "Blockable" mixed content
     case WebURLRequest::RequestContextBeacon:
     case WebURLRequest::RequestContextCSPReport:
     case WebURLRequest::RequestContextEmbed:
     case WebURLRequest::RequestContextEventSource:
     case WebURLRequest::RequestContextFetch:
     case WebURLRequest::RequestContextFont:
     case WebURLRequest::RequestContextForm:
@@ skipping 329 matching lines @@
 
     // See comment in shouldBlockFetch() about loading the main resource of a subframe.
     if (request.frameType() == WebURLRequest::FrameTypeNested && !SchemeRegistry::shouldTreatURLSchemeAsCORSEnabled(request.url().protocol())) {
         return ContextTypeOptionallyBlockable;
     }
 
     return contextTypeFromContext(request.requestContext(), mixedFrame);
 }
 
 } // namespace blink