Add explicit to core/fetch, core/loader and modules/websockets

third_party/WebKit/Source/core/loader/SinkDocument.h

 /*
  * Copyright (C) 2010 Apple 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 20 matching lines @@
 namespace blink {
 
 class SinkDocument final : public HTMLDocument {
 public:
     static SinkDocument* create(const DocumentInit& initializer = DocumentInit())
     {
         return new SinkDocument(initializer);
     }
 
 private:
-    SinkDocument(const DocumentInit&);
+    explicit SinkDocument(const DocumentInit&);
 
     DocumentParser* createParser() override;
 };
 
 
 } // namespace blink
 
 #endif // SinkDocument_h