CommandLine: deprecate another function on non-Windows

base/command_line.cc

Index: base/command_line.cc
diff --git a/base/command_line.cc b/base/command_line.cc
index 4d76ed08955a075bfd13873760a331c1b4a26555..477b4e72bb7e2d01b93ece352c8ab189f715717c 100644
--- a/base/command_line.cc
+++ b/base/command_line.cc
@@ -332,18 +332,18 @@ CommandLine::StringType CommandLine::GetSwitchValueNative(
 }
 
 FilePath CommandLine::GetProgram() const {
-  return FilePath::FromWStringHack(program());
+#if defined(OS_WIN)
+  return FilePath(program_);
+#else
+  DCHECK_GT(argv_.size(), 0U);
+  return FilePath(argv_[0]);
+#endif
 }
 
 #if defined(OS_WIN)
 std::wstring CommandLine::program() const {
   return program_;
 }
-#else
-std::wstring CommandLine::program() const {
-  DCHECK_GT(argv_.size(), 0U);
-  return base::SysNativeMBToWide(argv_[0]);
-}
 #endif
 
 #if defined(OS_POSIX)