Add FilePath::FromUTF8Unsafe() and FilePath::AsUTF8Unsafe().

The logic is moved from value_conversions.cc.
FilePath::FromUTF8Unsafe() should only be used when you are
sure that the input string is UTF-8. See the function comments
for why they have "Unsafe" in their names.

BUG=none
TEST=base_unittests

Review URL: http://codereview.chromium.org/8402008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@108246 0039d316-1c4b-4281-b951-d872f2087c98


CrOS-Libchrome-Original-Commit: 45440519a239ffad82425e08115d909fd82a1e9d
diff --git a/base/value_conversions.cc b/base/value_conversions.cc
index 64513d0..f4957a4 100644
--- a/base/value_conversions.cc
+++ b/base/value_conversions.cc
@@ -5,39 +5,14 @@
 #include "base/value_conversions.h"
 
 #include "base/file_path.h"
-#include "base/sys_string_conversions.h"
-#include "base/utf_string_conversions.h"
 #include "base/values.h"
 
 namespace base {
 
-namespace {
-
 // |Value| internally stores strings in UTF-8, so we have to convert from the
 // system native code to UTF-8 and back.
-
-std::string FilePathToUTF8(const FilePath& file_path) {
-#if defined(OS_POSIX)
-  return WideToUTF8(SysNativeMBToWide(file_path.value()));
-#else
-  return UTF16ToUTF8(file_path.value());
-#endif
-}
-
-FilePath UTF8ToFilePath(const std::string& str) {
-  FilePath::StringType result;
-#if defined(OS_POSIX)
-  result = SysWideToNativeMB(UTF8ToWide(str));
-#elif defined(OS_WIN)
-  result = UTF8ToUTF16(str);
-#endif
-  return FilePath(result);
-}
-
-}  // namespace
-
 StringValue* CreateFilePathValue(const FilePath& in_value) {
-  return new StringValue(FilePathToUTF8(in_value));
+  return new StringValue(in_value.AsUTF8Unsafe());
 }
 
 bool GetValueAsFilePath(const Value& value, FilePath* file_path) {
@@ -45,7 +20,7 @@
   if (!value.GetAsString(&str))
     return false;
   if (file_path)
-    *file_path = UTF8ToFilePath(str);
+    *file_path = FilePath::FromUTF8Unsafe(str);
   return true;
 }