Add initial version of retainers heap profile.

src/string-stream.cc

 // Copyright 2006-2008 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 233 matching lines @@
 
 
 void StringStream::Add(const char* format, FmtElm arg0, FmtElm arg1,
                        FmtElm arg2, FmtElm arg3) {
   const char argc = 4;
   FmtElm argv[argc] = { arg0, arg1, arg2, arg3 };
   Add(CStrVector(format), Vector<FmtElm>(argv, argc));
 }
 
 
-SmartPointer<const char> StringStream::ToCString() {
+SmartPointer<const char> StringStream::ToCString() const {
   char* str = NewArray<char>(length_ + 1);
   memcpy(str, buffer_, length_);
   str[length_] = '\0';
   return SmartPointer<const char>(str);
 }
 
 
 void StringStream::Log() {
   LOG(StringEvent("StackDump", buffer_));
 }
@@ skipping 310 matching lines @@
 
 // Only grow once to the maximum allowable size.
 char* NoAllocationStringAllocator::grow(unsigned* bytes) {
   ASSERT(size_ >= *bytes);
   *bytes = size_;
   return space_;
 }
 
 
 } }  // namespace v8::internal