Fix compiling of sync on linux.

chrome/browser/sync/util/path_helpers_posix.cc

 // Copyright (c) 2009 The Chromium 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 <pwd.h>
 #include <string.h>
 
+#include "chrome/browser/sync/notifier/base/string.h"
 #include "chrome/browser/sync/util/path_helpers.h"
 
 #if ((!defined(OS_LINUX)) && (!defined(OS_MACOSX)))
 #error Compile this file on Mac OS X or Linux only.
 #endif
 
 PathString ExpandTilde(const PathString& path) {
   if (path.empty())
     return path;
   if ('~' != path[0])
     return path;
   PathString ret;
   // TODO(sync): Consider using getpwuid_r.
   ret.insert(0, getpwuid(getuid())->pw_dir);
   ret.append(++path.begin(), path.end());
   return ret;
 }
 
 namespace {
 // TODO(sync): We really should use char[].
-string cache_dir_;
+  std::string cache_dir_;
 }
 
-void set_cache_dir(string cache_dir) {
+void set_cache_dir(std::string cache_dir) {
   CHECK(cache_dir_.empty());
   cache_dir_ = cache_dir;
 }
 
-string get_cache_dir() {
+std::string get_cache_dir() {
   CHECK(!cache_dir_.empty());
   return cache_dir_;
 }
 
 // On Posix, PathStrings are UTF-8, not UTF-16 as they are on Windows. Thus,
 // this function is different from the Windows version.
 PathString TruncatePathString(const PathString& original, int length) {
-  if (original.size() <= length)
+  if (original.size() <= static_cast<size_t>(length))
     return original;
   if (length <= 0)
     return original;
   PathString ret(original.begin(), original.begin() + length);
   COMPILE_ASSERT(sizeof(PathChar) == sizeof(uint8), PathStringNotUTF8);
   PathString::reverse_iterator last_char = ret.rbegin();
 
   // Values taken from
   // http://en.wikipedia.org/w/index.php?title=UTF-8&oldid=252875566
   if (0 == (*last_char & 0x80))
@@ skipping 27 matching lines @@
 
   // Invalid utf-8. chop off last "codepoint" and return.
   ret.resize(ret.size() - last_codepoint_len);
   return ret;
 }
 
 // Convert /s to :s.
 PathString MakePathComponentOSLegal(const PathString& component) {
   if (PathString::npos == component.find("/"))
     return PSTR("");
-  PathString new_name;
-  new_name.reserve(component.size());
-  StringReplace(component, "/", ":", true, &new_name);
+  PathString new_name(component);
+  notifier::StringReplace(&new_name, "/", ":", true);
   return new_name;
 }