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

src/factory.cc

Index: src/factory.cc
diff --git a/src/factory.cc b/src/factory.cc
index 10e70d909fdbf98be99fd436768170d9e621d3bb..8b842a733928f7425f73870b8c61523bc03ac84c 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -259,32 +259,6 @@ Handle<String> Factory::NewConsString(Handle<String> first,
 }
 
 
-template<typename SinkChar, typename StringType>
-Handle<String> ConcatStringContent(Handle<StringType> result,
-                                   Handle<String> first,
-                                   Handle<String> second) {
-  DisallowHeapAllocation pointer_stays_valid;
-  SinkChar* sink = result->GetChars();
-  String::WriteToFlat(*first, sink, 0, first->length());
-  String::WriteToFlat(*second, sink + first->length(), 0, second->length());
-  return result;
-}
-
-
-Handle<String> Factory::NewFlatConcatString(Handle<String> first,
-                                            Handle<String> second) {
-  int total_length = first->length() + second->length();
-  if (first->IsOneByteRepresentationUnderneath() &&
-      second->IsOneByteRepresentationUnderneath()) {
-    return ConcatStringContent<uint8_t>(
-        NewRawOneByteString(total_length), first, second);
-  } else {
-    return ConcatStringContent<uc16>(
-        NewRawTwoByteString(total_length), first, second);
-  }
-}
-
-
 Handle<String> Factory::NewSubString(Handle<String> str,
                                      int begin,
                                      int end) {