Various extension-related cleanup and simplifications.

src/extensions/externalize-string-extension.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 127 matching lines @@
     args.GetIsolate()->ThrowException(v8::String::NewFromUtf8(
         args.GetIsolate(),
         "isAsciiString() requires a single string argument."));
     return;
   }
   bool is_one_byte =
       Utils::OpenHandle(*args[0].As<v8::String>())->IsOneByteRepresentation();
   args.GetReturnValue().Set(is_one_byte);
 }
 
-
-void ExternalizeStringExtension::Register() {
-  static ExternalizeStringExtension externalize_extension;
-  static v8::DeclareExtension declaration(&externalize_extension);
-}
-
 } }  // namespace v8::internal