Reland "Optimize KURL protocols"

third_party/WebKit/Source/platform/weborigin/KURL.h

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2011, 2012 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
@@ skipping 178 matching lines @@
 
   const KURL* innerURL() const { return m_innerURL.get(); }
 
   bool isSafeToSendToAnotherThread() const;
 
  private:
   void init(const KURL& base,
             const String& relative,
             const WTF::TextEncoding* queryEncoding);
 
+  StringView componentStringView(const url::Component&) const;
   String componentString(const url::Component&) const;
-  String stringForInvalidComponent() const;
+  StringView stringViewForInvalidComponent() const;
 
   template <typename CHAR>
   void replaceComponents(const url::Replacements<CHAR>&);
 
   void initInnerURL();
-  void initProtocolIsInHTTPFamily();
+  void initProtocolMetadata();
 
   bool m_isValid;
   bool m_protocolIsInHTTPFamily;
+
+  // Keep a separate string for the protocol to avoid copious copies for
+  // protocol(). Normally this will be Atomic, except when constructed via
+  // KURL::copy(), which is deep.
+  String m_protocol;
+
   url::Parsed m_parsed;
   String m_string;
   std::unique_ptr<KURL> m_innerURL;
 };
 
 PLATFORM_EXPORT bool operator==(const KURL&, const KURL&);
 PLATFORM_EXPORT bool operator==(const KURL&, const String&);
 PLATFORM_EXPORT bool operator==(const String&, const KURL&);
 PLATFORM_EXPORT bool operator!=(const KURL&, const KURL&);
 PLATFORM_EXPORT bool operator!=(const KURL&, const String&);
@@ skipping 61 matching lines @@
 
 // KURLHash is the default hash for String
 template <>
 struct DefaultHash<blink::KURL> {
   typedef blink::KURLHash Hash;
 };
 
 }  // namespace WTF
 
 #endif  // KURL_h