Rollback of r15267, r15263, r15193 in trunk branch in preparation for 3.19 branch

src/factory.h

 // Copyright 2012 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 134 matching lines @@
       int length,
       PretenureFlag pretenure = NOT_TENURED);
   Handle<SeqTwoByteString> NewRawTwoByteString(
       int length,
       PretenureFlag pretenure = NOT_TENURED);
 
   // Create a new cons string object which consists of a pair of strings.
   Handle<String> NewConsString(Handle<String> first,
                                Handle<String> second);
 
-  // Create a new sequential string containing the concatenation of the inputs.
-  Handle<String> NewFlatConcatString(Handle<String> first,
-                                     Handle<String> second);
-
   // Create a new string object which holds a substring of a string.
   Handle<String> NewSubString(Handle<String> str,
                               int begin,
                               int end);
 
   // Create a new string object which holds a proper substring of a string.
   Handle<String> NewProperSubString(Handle<String> str,
                                     int begin,
                                     int end);
 
@@ skipping 390 matching lines @@
   } else {
     return NewNumber(static_cast<double>(value), pretenure);
   }
 }
 
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_FACTORY_H_