Revert "Use CFX_RetainPtr to ref count CFX_ByteString"

core/fxcrt/fx_basic_bstring_unittest.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/fxcrt/include/fx_string.h"
 #include "testing/fx_string_testhelpers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 TEST(fxcrt, ByteStringOperatorSubscript) {
   // CFX_ByteString includes the NUL terminator for non-empty strings.
@@ skipping 270 matching lines @@
   assigned_nullptr_string = (const FX_CHAR*)nullptr;
   EXPECT_EQ(assigned_nullptr_string.GetPtr(), nullptr);
   EXPECT_EQ(assigned_nullptr_string.GetLength(), 0);
   EXPECT_TRUE(assigned_nullptr_string.IsEmpty());
   EXPECT_EQ(null_string, assigned_nullptr_string);
 
   CFX_ByteStringC non_null_string("a");
   EXPECT_NE(null_string, non_null_string);
 }
 
-TEST(fxcrt, ByteStringConcat) {
+TEST(fxcrt, ByteStringConcatInPlace) {
   CFX_ByteString fred;
-  fred.Concat("FRED", 4);
+  fred.ConcatInPlace(4, "FRED");
   EXPECT_EQ("FRED", fred);
 
-  fred.Concat("DY", 2);
+  fred.ConcatInPlace(2, "DY");
   EXPECT_EQ("FREDDY", fred);
 
   fred.Delete(3, 3);
   EXPECT_EQ("FRE", fred);
 
-  fred.Concat("D", 1);
+  fred.ConcatInPlace(1, "D");
   EXPECT_EQ("FRED", fred);
 
   CFX_ByteString copy = fred;
-  fred.Concat("DY", 2);
+  fred.ConcatInPlace(2, "DY");
   EXPECT_EQ("FREDDY", fred);
   EXPECT_EQ("FRED", copy);
 
   // Test invalid arguments.
   copy = fred;
-  fred.Concat("freddy", -6);
+  fred.ConcatInPlace(-6, "freddy");
   CFX_ByteString not_aliased("xxxxxx");
   EXPECT_EQ("FREDDY", fred);
   EXPECT_EQ("xxxxxx", not_aliased);
 }
 
 TEST(fxcrt, ByteStringCNotNull) {
   CFX_ByteStringC string3("abc");
   CFX_ByteStringC string6("abcdef");
   CFX_ByteStringC alternate_string3("abcdef", 3);
   CFX_ByteStringC embedded_nul_string7("abc\0def", 7);
@@ skipping 357 matching lines @@
   }
 }
 
 TEST(fxcrt, EmptyByteString) {
   CFX_ByteString empty_str;
   EXPECT_TRUE(empty_str.IsEmpty());
   EXPECT_EQ(0, empty_str.GetLength());
   const FX_CHAR* cstr = empty_str.c_str();
   EXPECT_EQ(0, FXSYS_strlen(cstr));
 }